"[…] This service is being developed in partnership with Flower AI, which leverages Nvidia’s confidential compute to provide private remote processing in the event a user’s PC isn’t powerful enough. Sipes emphasizes that any remote processing features attached to Thunderbird Assist will always be optional, in the interest of ensuring complete user privacy.”

That’s a lot of words to say “we made an AI that totally won’t suck up your data, trust me bro”