>How does this work long-term? Is the new reality going to be picking an AI provider for all of your SaSS tooling,

I suspect the goal is partly starting a walled garden.

"Llms are interchangeable? Our harness/toolset isn't".

It's a way to get a moat I guess.

It doesn't sound like a business for the scale they're aiming for though. Taking a bite of the MS office's pie doesn't seem to me like a trillion dollar company move.