The famous deal where Microsoft promised to keep bringing Office to the Mac for five years was in 1997. Those five years encompassed the classic MacOS to OS X transition. Apple’s five year roadmap was far from a secret to developers.
The whole Carbon API for OS X was done after major developers insisted on it to bring their apps to OS X.
Adobe and Microsoft committed to port their software to x86 when Apple announced the transition in 2005.
Heck Microsoft was on stage committing to the Mac in 1984.
I believe you're conflating "Apple needing an Office story to sell to enterprise" with "Apple needing pre-commitment from Microsoft before implementing a hardware or OS transition". Those transitions would've happened regardless of whether we lost a few A-list developers.
Apple did not ask permission from developers before deciding to advance their platform.
But in fact, major developers vetoing the idea of porting directly to Objective C from day one gave rise to Carbon.
No, those transitions started (and became sure things) long before there was any commitment from "A-list" developers to support them. Getting commitment was an orthogonal task, and itself took significant technical and relationship work from both Apple and the developers. (Note: I was in developer relations for a few of these transitions.)
> Whether there are a lot of Indy developers on the Mac doesn’t matter.
Indie developers matter, not least of which because they're typically the first to adopt new Apple-only technologies.