There is already a variant where they try to get someone to say „yes“ and just use a recording of it to use as „proof“ that you agreed to some contract.
I actually don’t answer unknown callers with “hello” or any words actually. I simply just say “mmmhhmm” or make a dumb sound if it is automated it will trigger the automatic message. Someone asked why and I said voice cloning software they said wtf you have nothing to steal. Just feels risky idk why.