Okay re-reading the original email, it looks like they're using Activision as a shortened way of saying Activision-Blizzard.
So Crash, Spyro, Diablo and Overwatch were just ripped from the original deal, Lul.
Doesn't really matter for Diablo and Overwatch though, neither are getting a sequel anytime soon.
But it looks like Microsoft just kept the door open for exclusive Crash and Spyro while the original deal offered them both to remain on PlayStation.