HSMTMTS Creator Tim Federle on Olivia Rodrigo's 'Beautiful' Exit and Returning to Roots in Season 4

Anne Marie Fox/Disney

High School Musical: The Musical: The Series took fans on an emotional roller coaster for the season 3 finale.

After taking place at the iconic East High from the High School Musical films the past two seasons, season 3 took place at summer camp — a location decision made largely because of the COVID-19 pandemic, according to creator Tim Federle.

"We had an entire [season 2], episode 12 written, table read, giant 'Menkies' performance [that we scrapped]," Federle tells PEOPLE. "We had so many COVID concerns in Salt Lake City and many of us had been in Salt Lake for over a year for season 2 that we ended up pulling the plug early because I just needed to get the cast back home to safety."

In many ways, Federle adds that the change of scenery ended up being the perfect opportunity for the show to get back to its roots. "We had a real plan for, which was: If we do Frozen, [Joshua Bassett] can sing Kristoff's lullaby, [Dara Reneé] is gonna inspire young Black princesses everywhere when they see her sing, 'Let It Go,' Sofia Wylie is gonna get to play a lighter side of Gina as Anna.' There was such a plan to return to our roots of a group of theater kids putting on a show."

Anne Marie Fox/Disney

As the students put on the magical production of Frozen in the season 3 finale, the episode feels like the start of something new for many characters as they explore new relationships and self-discoveries. It also serves as a poignant goodbye to Nini Salazar-Roberts (Olivia Rodrigo) as she officially departs from the show.

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Federle reveals that the season 3 episodes for Rodrigo — who appeared only as a guest star this season — were shot in three days before the singer went on her Sour tour. "All of that was shot with this crazy schedule in mind, which Olivia deserves because she is the queen of the world," he says.

In writing her exit, Federle says he really wanted to portray the complexities of endings. "What I wanted to say with Nini's story [and] with EJ's (Matt Cornett) story is that everyone can't have a perfect, happy ending every season, but there's always a future where you're driving off into something that could be even better or at least teach you something about yourself," he explains.

"The song 'Born to Be Brave' is sentimental to me. I think it's the theme of the entire series. We've always strived to tell stories that are representative and modern and queer and true and I just felt like there was no more beautiful way of doing that than reminding Nini that when she gets in the car, those voices are always gonna be with her."

Anne Marie Fox/Disney

As Nini drives off into the night, the show also wraps up her storyline with Bassett's Ricky as she gifts him a lottery ticket for his 18th birthday, completing his summer bucket list.

"The lottery ticket was a pitch from Ilana Wolpert [in our writer's room] and was to say our fundamental dynamic as Ricky and Nini may have changed, but [they] will always know things about the other one that no one else knows. [They'll] always be each other's first loves. I thought that was a really poignant beat."

"I remember on the day we shot it, Josh pulled me aside. He was like, 'Hey, by the way, how am I reacting to the lottery ticket?' And I was like, 'React to it however you want because whatever mix of feelings Ricky has is true.'"

RELATED: Olivia Rodrigo Sings the 'Best Is Yet to Come' Ahead of Nini's Exit

As Nini and Ricky's story comes to a close, his journey with Gina is seemingly just getting started as she professes her feelings for Ricky at the end of season 3.

"I had written an entire original version where it was Ricky declaring his feelings for Gina and then I sort of realized I've done that before," Federle reveals. "Ricky had a break the internet, I love you speech and I thought this time it's about Gina being in the driver's seat."

For the special scene, Federle reveals that he was so nervous about leaks getting out, that he actually didn't let the crew read the script. "Only Josh and Sofia and the director read that scene. We literally sent the rest of the cast out into the hall. We broke as many of the crew as we could. We shot it as privately as possible in two takes. To me, it was a really thrilling midpoint to where these two characters are going next."

Anne Marie Fox/Disney

Following the announcement that season 4 will revolve around the fictional filming of High School Musical 4, things are about to get even more meta for the Wildcats as they return to East High for their senior year.

While a handful of OG HSM stars have already appeared on the series, including Lucas Grabeel, Kaycee Stroh and Corbin Bleu, Federle confirms that an invitation has been extended to all of the original HSM stars to cameo in season 4.

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"Now it's a matter of juggling and holding my breath and praying and lighting candles and seeing who wants to come play with us," he says. "So I have high hopes, but I can tell you we've engaged a lot of people and it's gonna be a really exciting season."

As for the rest of the cast, Federle adds that almost everyone in the season 3 finale "is going to make their way back into the show" next season, including new additions Maddox (Saylor Bell) and Jet (Adrian Lyles) as well as Cornett's EJ, who recently graduated. "If you love somebody in season 3, they'll probably be back, but we're always sort of juggling the number of people whose stories we're telling."

Anne Marie Fox/Disney

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Going into season 4, Federle adds that the upcoming season is a "real return to the original" season. "[It's] the real return to why the show got greenlit in the first place, which is real theater kids singing at this iconic location, aka East High."

Looking even further to the future, Federle admits he already has an endgame for the show in mind but doesn't "take for granted future seasons." "I think I've glibly in the past said we're gonna go seven seasons and I would still love that but I think other than Cobra Kai we're just about the longest running reboot there is right now, which we're all super, super grateful and proud of. I definitely have endgames in mind for all of the characters in terms of how long the show goes. I think that's gonna be a decision that Disney and I come to together."

When the show's final season does come, Federle adds that the door is always open for anyone to return, including Rodrigo. "There's a lot of people who have become a part of our extended family and I think when we reach that day, my hope would be that it's just a big cheerful, joyful party on set."

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High School Musical: The Musical: The Series season 3 is currently streaming on Disney+.