I have finally made it to the last episode of the first season!
The episode starts with Tsubasa informing the understudies that they will not be able to continue the concert on Lancastar because DES is coming after them. Everyone is upset, and Yuuka is the one that brings up the possibility that Lancastar will be completely under the Entertainment Ban if they do not finish the concert. This means that they will never be able to come back to Lancastar.
After the understudies have successfully come back to the Katyusha, Tsubasa is not sure what to do and remembers what Acchan said about performing at a concert where no one is waiting for them: