Except if the event is on the 21st as rumoured. That's a Monday. Official releases always happen on Tuesday's. Apple has all sorts of Apple vs FBI on the 22nd, so doesn't seem like they'll release anything then.
Putting the most likely scenario of releasing on the 15th. At least to me at least.
I think the question becomes, are they going to squeeze a 6th beta in this next week or are they going to just update the build number from beta 5 (which is typically what they do) and release that for the official release.
How much notice do they normally give press before a keynote? I'm curious when it's going to be, a lot of hype around this event.
And a lot of betas for 9.3!