This is my big concern. Right now Gemini is an option you can switch on to replace the existing assistant, which I expect has similar terms. But how long will it be until Google just integrates this with their email, search, and online office suite with no options to disable it? They'll tout it as an improvement and new features.
Microsoft at least has to cater to business customers, so there will be options for systems administrators to opt-out for longer. With their government contracts they will have to prove adequate security. I still don't like the AI push, or Microsoft as a whole, but I trust them not to have a data leak, or to sell business data to whoever. They don't have overwhelming financial incentives in advertising or data collection for it, just normal sized incentives.
On the other hand, Google's biggest revenue stream is advertising, and that works due to the absurd amount of non-paying users they have with their free services. They have no business or financial incentives whatsoever to not just offer all this data they collect up on a silver platter. No incentives not to train horrible dystopian AI to maximize advertising effectiveness through A/B testing specific market/interest groups on an unimaginable scale.
Google also has a history of collecting more data than they were allowed to, pinning it on a "rogue employee enabling a feature they were told to disable" when they are caught, and then proceeding to use that data anyway for their projects after the news dies down.
I've always wanted to see a true "AI" personal assistant, leveraging tech to make lives easier, but this shit is not the way.