This sounds interesting indeed, and I'm curious to see it in action. I wasn't able to tune in to today's keynote, because I was with a neighbor across the hall at his place. He has an iPad and an Android phone, but is not that technical. As a proud VoiceOver user since about 2014, I would guess that Apple's new speech recognition thing will at least be somewhat accessible with VoiceOver right from the start. I personally have found Apple to have a very good track record when it comes to their screen reader. Siri might be a somewhat different story, but I guess only time will tell.