How do these changes help to funnel users towards Azure and Office Copilot 365?

Folks could have used those services even if Windows itself wasn't getting clanked, right?

It's simple advertising. People have a higher chance to use a product if it is advertised to them. I don't think there is a microsoft app these days that doesn't have a copilot logo visible in it at all times (even Paint).

That's like asking how installing a default browser helps boost that browsers market share.

Does that answer your question

No, because of course I want to use a browser, so I will download one if there isn't a default.

Not the case for Azure or Office

Despite what non lawyers may have told you, corporations are not legally obliged to chase short term profit at the expense of everything else!