Supposably from what I've seen, at the end of September. Now that might vary from phone to phone by their provider but that's kind of just an assumption also. I have the factory unlocked version so I myself in particular have to wait longer because of this which they did that with Android 10 update a few months back.
As I mentioned from earlier it just varies on your carrier and the developer themselves I guess you can say. I've been checking mine periodically and besides the latest security update that I got the other day I still haven't received this but I'm also hopeful that when the time comes when Android 11 comes out we'll also get OneUI 3.0 so the waiting game more or less.