Zoom already does 256bit AES end-to-end encryption. From what I understand it isn't the live calls but the files and recorded calls you save on their servers after are what they would use for AI training.

Zoom already updated their TOS a few hours ago to supposedly address the issue. https://gizmodo.com/zoom-ai-privacy-policy-train-on-your-data-1850712655

Update, August 7, 5:06 p.m.: After this story was published, Zoom issued an update to its Terms of Service. The article has been updated to reflect the change.