this basically boils down to TOFU (trust on first use), but the trust does not perpetuate across uses, so it’s more like, TOAU (trust on any use). The trust is ephemeral, the meeting is ephemeral, the ID is ephemeral. For a lot of meetings, this is perfectly acceptable.

I think I would call this TFSU (Trust For Single Use). Trust On Any Use sounds like complete and total trust.