'High School Musical 4' rumors and updates: Ashley Tisdale confirms not returning for reboot; Zac Efron, Vanessa Hudgens already filming?

Disney's hit movie franchise "High School Musical" will soon have its much-anticipated reboot titled "High School Musical 4", and fans will surely feel nostalgic as some of the original cast members are speculated to make a cameo appearance.
Rumor has it that the franchise's original lead stars Zac Efron and Vanessa Hudgens will be joining the upcoming film, as they are set to make a special appearance. Efron posted old photos of him and his "HSM" castmates via Instagram last month, adding more fuel to the speculation that he will return. The caption for the photo dating back to 2008 reads: "So grateful I came across this picture... With the o.g. crew during one of the most cherished and exciting times of my life. Love you guys forever. #fbf"
Reports claim that the duo already started shooting scenes, but Disney's representatives have yet to confirm this. However, GamenGuide notes that it might be unlikely to be true since they are both currently busy with other commitments.
Unfortunately for Sharpay's fans, Ashley Tisdale already announced that she will not be back to reprise her role, even in a cameo appearance. The actress caught up with New You recently, and she confirmed that she will not join the movie. "Looking back, it was such a perfect thing for its time and was so pure that I just don't know how you go from there," Tisdale said. "High School Musical didn't make us, we made High School Musical because of our friendship, how close we were, and the magic there at the time. Kenny Ortega just made it what it was. Disney is an amazing company so I'm sure they'll find some way to do it."
Casting for new leads began early last month, and as noted by Entertainment Weekly, the story will pick up on Albuquerque, New Mexico's East High Wildcats along with their cross-town competitors, the West High Knights. Following Tisdale's announcement to bow out from the upcoming installment, none of the original cast members have confirmed their involvement in the film.
Disney has yet to announce a definitive premiere date for "High School Musical 4," but more details are expected to be released soon.