Re: I'd love to know the rationale...
"Apple knows it can force people to migrate over time"
It's the MacOS Classic vs OS X (or the artist currently known as macOS) scenario all over again, rinse, repeat... I think the world got over losing Classic 9.2, they'll get over losing 32bit apps.
As mentioned above, Adobe knew for a long time that Apple is fleeing 32bitsville, and not looking back.