Currently, if mod_muc_mam isn't loaded (whether directly or undirectly through mod_mam), the MUC component won't support stanzaIDs and occupantIDs. But the XEPs don't specify such dependence. The decoupling will allow features like moderation, retraction, replies and reactions to work when MAM is disabled. Moreover, the upcoming GC3 spec will make occupantIDs mandatory, but it will probably keep MAM optional. So, Prosody will eventually have to decouple the features anyway.

It seems I was mistaken about occupantID support depending on mod_muc_mam. But the issue still remains with regards to stanzaID support. Unfortunately I can't edit the title / description.

Stanza IDs without MAM wouldn't be very useful. In fact anything without MAM isn't very useful. You might see a reaction, reply or read marker, but never know what it was reacting to, unless you were lucky enough to be online at the time the original message was sent. For iOS users for example, that would mean they would have to keep the app in the foreground constantly. If someone really wants this, it would be a very short module to just make up a UUID and attach it as a stanza-id. It would just lead to a terrible experience though, and I don't think it's desirable enough to support this in Prosody. It could just be a community module.

• title Decouple stanzaID (XEP-0359) and occupantID (XEP-0421) support from mod_muc_mam Add stanza-id (XEP-0359) when MAM is not enabled