This seems to be getting published everywhere like it's new, and maybe it's a new exploit, however a group was able to do this in 2021 (which was fixed, so not clear if this is a new exploit):
https://cyberhoot.com/blog/apple-airdrop-vulnerability/
This is indeed not new. In fact, it’s documented by Apple that AirDrop reveals a hash of the sender‘s email address and phone number. Reversing these is trivial (for the phone number)/usually doable (for the email address).