No.
Even if it's built in a fully-local, privacy-first manner, I have no confidence it will stay that way.
Microsoft has shown itself again and again to prioritize turning Windows into an ad platform, over sound technical decisions.
Why would this be any different?
I could be ignorant. I could be paranoid. I could be wrong. I want to be wrong.
But I don't think I am. And you aren't either. That's what's scary.
And when this feature exists on all machines, and Microsoft has access to the codebase, you don't think other portions of the company will pitch a "+X revenue if we just used it for Y" re-use of the existing data?
Most of Google and Apple's recent user-hostile decisions can be traced directly back to too much potential revenue to refuse (ad tracking data, app store lock-in). Microsoft isn't immune to those same strategic marketing pressures.
Some data is too tempting to use for evil, that the only sane approach is to ensure there's no centralized manner to access it at scale.