I doubt it. It would be really obvious because of the extra data traffic. People who go bananas if they found out Google chews through their monthly plan to exfiltrate audio.
Although Google (and Apple, and all the others) are working hard to embed AI onto your cellphone, not for your own convenience but to implement client-side surveillance - i.e. digest what you see and do and distill the surveillance data on your device before it even hits the internet - so that the surveillance doesn’t attract undue attention.
But we’re not there quite yet, and I don’t believe even Google could get away with real, proper audio surveillance today.
That’s probably the reason why they want to create this bogus “note taking” service: to have a legitimate excuse to listen in on your audio.