It would be pretty easy to test, too.
Get a pre-paid phone. Set up a brand-new Google or Apple account. Activate phone using the new account. Put it through its paces for a few hours and note the ads you get.
Shoot the shit with your friends and family with the phone on the table for a few hours.
Put the phone through its paces again and note the ads you get.
AI acceleration ASICs are already in a lot of hardware these days. It doesn’t take a whole lot anymore for it to be both cheap and feasible.