Yury asked me to weigh in here, since I guess between him and Andrew there's some uncertainty about whether reverting is the right choice or not. I can't answer that, but I can share some thoughts.

Unfortunately, I wasn't aware of the Stream PR when it was first being written and reviewed; I only discovered the change a month or two ago, by accident. If I had, I'd have said something like:

> This is definitely a major improvement over the old API, that fixes some important issues, which is awesome. But, it only fixes some of the issues, not all of them, and it's really difficult to change things in asyncio after they ship. So there's a tricky question: do you want to ship this now so users can start taking advantage of its improvements immediately, or do you want to wait to make sure you don't have to do multiple rounds of changes?

Of course, now we're in a situation where it's already merged, which makes things more awkward. But maybe it will clarify things a bit to do a thought experiment: if the asyncio.Stream API was a PR that hadn't been merged yet and we were considering merging it – would you hit the green merge button, given what we know now, or would you hold off for 3.9?