“You cannot dangle what people need to effectively work in front of them like a carrot and subtly threaten to take it away. It’s ableist. You wouldn’t dare to do that with elevators or other accessibility features at the office, so don’t do it with that either.”
This is only because there's usually legal protection for that kinds of accessibility features. If employers could legally, it would be way more common to threaten to take them away.
I have no doubt there are some that do so illegally.
When I was young, I worked in a call center in which the bathroom was taken away as a punishment for bad rates on multiple occasions, until someone called the Dept. of Labor over it.