Things will be muddled in any way or another. Making a new NIP doesn't really change that. You're just moving the muddling to another department, but you'll have to deal with it anyway. It's like making a new kind with a different content-type, or a new "version". It's all cosmetics for "making a new protocol". Essentially it all comes down to creating new work for everybody to maintain everything at the same time and wrap their heads around the new stuff. In this case I think it is worth it. But honestly, I just wish someone did something different. Would be nice to have a more specialized and more efficient Nostr-like protocol around "chat servers" (as opposed to Nostr relays). Reuse Nostr identities, use Nostr for signaling, I don't know, but don't send the actual messages as Nostr events to relays, that is ugly.