All "dexited" moves are returning as well. This means that you can use Pursuit again! All "dexited" moves have Max Powers based on a table posted later on in this thread. For example, Pursuit turns into a 90-Base Power Max Darkness.
Source
Yep, you can use Pursuit, Hidden Power and all other removed moves along with Megas, z-moves and removed Pokemon as well. The source also lists all the way the mechanics work, so you should probably read it once if you ever a play a Nat Dex format (Nat Dex OU, UU, Monotype or AG).
Hope this helps!