They are called Ultimate Battle and Brainiac Maniac. And I don't know exactly how removing a few songs frees up a "ton" of space (if that is really why this was done), but someone was definitely not thinking clearly when he or she made this decision... Those are in my opinion the coolest songs in the whole game besides the Neon Mixtape Tour songs! At the very least give us players the option to choose between versions with and without them. Whoever wants more space - download a version without the songs. There is already considerable backlash in other sites about this:
https://gamefaqs.gamespot.com/boards/717906-plants-vs-zombies-2-its-about-time/75720932
https://www.reddit.com/r/PlantsVSZombies/comments/7g0ekk/why_is_ultimate_battle_and_brainiac_maniac/
Just make versions with and without the music. Its so simple, damn it! If they were to remove transactions though I'm sure EA wouldn't have been so decisive. Funny how you must sacrifice good features in order to fill a product with arguably questionable ones...
Bring back Ultimate Battle and Brainiac Maniac!