Yeah, I didn't realize that it could be used for much more than chat. So many amazing possibilities. While it might be hard to imagine a chat group with thousands to hundreds-of-thousands, a private follow/subscription list could easily reach those numbers. The scaling of MLS much more relevant in that case. Really interesting.

As there isn't metadata, only the group id/nonce, I imagine blind signature systems/ecash will be necessary to prevent spam on relays for these types of events. It also won't require auth that would add metadata.