Has Apple provided any additional information on the accessibility improvements coming to Xcode?
In the WWDC state of the union address it was stated that the Xcode beta had voiceover accessibility for interface builder. Was this explained in more detail in another WWDC session or is the only information released from Apple about this the 10 second mention in the state of the union address?
No, Apple has not provided any public information about Xcode 8 accessibility improvements.
Best advice I can provide is to download the beta and experiment. Just keep in mind that Apple makes drastic changes between one beta and the next.