TL;DR: Dana has been harboring some resentment over the way the Bucks were treated after Brawl Out. While The Elite themselves have decided to let bygones be bygones, she was never that happy with the situation.
Morffi, OTOH, simply had a better offer elsewhere.
I dunno that the mouthpiece of Punk is necessarily a reliable source on what Dana Massie was making, but even if accurate, given the wins AEW had merch wise on the retail side of things it might not be a surprise. Apart from the snow globe that never actually shipped, most of the complaints about merch are more around not having enough at live events; and that’s a factor of the partnership with PWT as much as anything.