I think the point here is that a patch in Staging is unlike a patch in Development. Once accepted, it's not supposed to just sit there and silently make things better, it's supposed to continue to develop (and/or get wider testing) and eventually land in Development in some form. It seems the Staging maintainers have settled on using Bugzilla to track that.
We could perhaps have a process where patches for Staging are first submitted to a mailing list, then when they're accepted into Staging a bug is created for them. That would give us consistency in the submission process, but it breaks up the discussion. And since patches are going to be picked up from wine-patches, it sounds like we'll sort of have that anyway (but with more flexibility for contributors)?
I think the only question here is whether submitting through bugzilla as an intermediate step misses something important that we'd get from the mailing list. If a patch is added to Staging, improved by others, and eventually sent to wine-patches, it may end up without a sign-off from the original author. Or, if we're picking up patches from bugzilla, maybe there's a risk that the original author doesn't understand they're making a contribution to Wine? I don't have a position on whether these are real problems, just seems worth considering.
I feel like a bugzilla keyword might be better than using the staging product. Often, there's going to be an existing Wine bug that will have any proposed patch attached to it, and I'm not sure it makes sense to file a new bug just to bring the patch to the attention of the Staging maintainers. Also, if the bug is in the Wine product, it can use a Wine component, which may bring it to the attention of people with an interest in that component.