As I think I’ve laid out in this thread 3x now: we’ve frequently seen 6 betas for a point release. We are on number 5 and number 6 would drop early next week (5/13 or 14). In all likelihood, that will also be the release candidate build. If that pans out, that same build will be released to the public on or about 5/20.
5/27 is Memorial Day and begins the short week prior to WWDC. It stands to reason that Apple will not release a major feature update in a short week during which its engineers are gearing up to the most significant software event of the Apple year. They are pushing the envelope a bit, as it is, given the importance of the TV updates coming with 12.3.
Dark horse candidates for release dates:
-next week (5/13): certainly possible, which would make beta 5 the release candidate build. I don’t recall Apple stopping at 5 betas before, but where we find ourselves on the overall version release calendar might make that a bit more realistic than normal.
-With iOS 13 beta 1 at WWDC on 6/3 or 6/4: No reason it couldn’t since most users will not be on the betas. Seems unlikely, though, in that a major functionality update would be overshadowed by iOS 13
So, there you have my own speculation, which is nothing more than that.