^
If we believe in Kawamori, it's up to you... it could also mean that
Spoiler for light novel supposed first spoilers:
Sheryl's giving her farewell concert and begins to start her "journey across the universe" (the journey of hope Kawamori hinted?).
Probably to search for Alto (who is now confirmed alive, instead of a goner). Actually I LIKE that scenario the best. Since I want hime to be the damsel in distress, rescued by Gar!Sheryl from the paws of the Vajra Queen. She'll sweep him off his feet and carry him back to Frontier one day?
Of course maybe Ranka and Sheryl are trolling an embarrassed Alto with a suggestive concert (considering the lyrics). And he gets to dance again... on the stage. It's up to you. But either way, it seems we can picture the best ending possible.