Or, Apple will be ok with the level of bugs in the last or next release (which could be tomorrow, who knows due to last week's late release and the holiday in the US today).
There's always been a minimum of 12 days between the last build and GM being released to the Developers, and longest was 29 days. Don't forget they have to put iOS 14 the new devices before they are shipped, so that's why there's a minimum gap between the last build we get and GM.
Going by your latest date, the last build would have to be 29th/30th September, or next week at your earliest guess.
Also, it has been said by someone with a good track record that iOS 14 GM will come in September.....
I think that 1 more beta tops before we get to GM, as mostly the current build is one of the better ones, and way less buggy than iOS 12 or 13 were at GM.
I like that this beta cycle for iOS 14 has had some mystery and abnormality to it!
I'm not confident there will be a beta this week, but I will say that if we don't get one next week, then I don't expect any more betas and we will be awaiting the GM.