VoiceOver does not speak the newly focused item in the sample app on Mac when navigating by keyboard

I just tried the sample app from the presentation, and found that on Mac, when navigating the list of coffees with the arrow keys, and VoiceOver is running, the focus changes, the accessibility label gets updated for the table view, but VoiceOver remains silent. I assume this is a bug in the beta currently?

What I did was:

1. Run the sample app.

2. Turn on VoiceOver.

3. Navigate to the table of coffees.

4. Press up and down arrows to select one.

5. VoiceOver remains silent. Only if I use VoiceOver commands to select a coffee, and then press VO+Space to activate it, does VoiceOver speak the item.