It's an interesting distinction for sure. Perhaps "Activate menu" and "Deactivate menu" would work too, particularly as there's no reference to visual things - what would "expanding" on the screen mean in the context of a blind user?

Not all screen reader users are blind though. There are plenty of people with enough vision to see the screen, but cannot easily read the text on the screen. And on mobile where users interact with the screen reader via the touch screen, expand/collapse or show/hide fit the bill perfectly.