What HAAS probably will do; Come out with a statement that says they have talked about the situation internally, come up with an 'ultimatium' (Because it gives the impression of being 'serious', without having to be) of "Don't do that again or you might find yourself without a seat". Some people will applaud this decision because of the ultimatum. However, I wouldn't be suprised when the next thing happens, HAAS find some sort of excuse to let him continue to drive. Whenever he has racked up enough negativity to which even HAAS can't turn from, they might have him sitting on the bench for a while and let their reserve driver drive for a race or two. Then, Mazepin will be back into the seat "having learned his lesson".
Essentially, HAAS will try to buy as much time as they possibly can. Only when it truly hits the boiling point, when every F1 news station is bringing it up, will they have a think about replacing him.
I struggle to see them ejecting him. Because it's never that easy. Albeit in this situation, it probably should be.