I think iOS 13.1 will be the GM for iOS 13 release since there are only one iOS 13 beta profile and Apple will seed the GM next Tuesday to the devices have the iOS 13 beta profile. As we all know, it is impossible to downgrade via OTA (,and wiping the whole device storage). Therefore, the GM build must have a build number same as or ahead of the iOS 13.1 beta 2 build number.
Moreover, 13.1 betas have "A" in the build number unlike the previous X.1 betas that have "B" in the build number. It indicates that 13.1 betas are in the same branch with the iOS 13.0 betas.
Probably, iOS 13.1 will be the release. This seems like unusual but 10.0.1 was the GM for iOS 10. Naming the release 13.1 makes sense because there are features such as Automations packed into 13.1 which were disabled in iOS 13.0.
We will see next week, as the GM Will be out on 10th.
People on the developer and public beta are warned not to run it on their main device. So, if Apple releases 13.0, then people on 13.1 beta 2 could either wipe and go in 13.0 or stick with 13.1 beta until 13.1 comes out.
There is about 2 actual features being added back in, and they’re not big really. That’s by the by, though.