I'm no expert on talkback, but I played around with the new controls today. It looks to be working about as well as it does today. Some notes:

1) We now have disabled mute/fullscreen buttons showing up, and talkback will read both of those normally without indicating that they're disabled.

2) Talkback reads the scrubber weirdly (reads out some non-user-friendly number), but this already happens on legacy and IIRC there's a longstanding bug out for it

3) One thing we wanted to check was that we correctly read the "Double tap to skip" message. Two notes from that:
  3a) I couldn't even select that text. Firstly, it only shows up while scrubbing, and so the user can't select the text since the focus will have to be on the scrubber/timeline. Secondly, even when I hacked it to stay visible even when not scrubbing, it still couldn't be selected/read for some reason.
  3b) I'm not sure you *can* double-tap to skip while talkback is on. Again I'm no expert, but IIUC you have to select a button and then double-tap to click, but it automatically clicks the middle, so the user can only click on the play button and not on the sides. Therefore, with talkback you can't use this feature anyway. 

1. Because we mark the button as disabled with the HTML attribute, I would expect things to work automatically. What happens for a `<input type=button disabled value=foo>`?

2. SGTM

3. What you describe SGTM. If the feature can't be used but also isn't advertised, it's probably fine. I'm not aware of a way to double tap with TalkBack and I'm not certain it's a practical gesture given that we require it to be at a specific place in the video. We should check with lpalmaro@ in the accessibility review if that's okay though.

I confirmed that the disabled state not being vocalised is a bug ( bug 827805 ). I think we can close this. There will be follow-up a11y bugs but not about TalkBack labels AFAICT.