> Your proposal is mixing both kinds of change in the same paper — which is 100% fine IMHO, but I'd like a nice clear table of which of your changes fall into which bucket, so that the reader can be informed.
> This is significant for programmers, but also significant for compiler vendors, too, because they're the ones who will have to craft the wording of their compiler diagnostics for those two distinct cases.

Well, I don't think it's 100% necessary for the proposal but an
informative annex that includes a big table summarizing it all may be
helpful.

I'd be grateful for contributions
(https://github.com/Eisenwave/cpp-proposals/blob/master/src/oxford-variadic-comma.bs).
Not sure if I'll find the time to do that myself.