No UA flight departs from T5 and so this thread is probably better off in one of the forums for airlines that do operate out of T5 or in a more general airport discussion forum. But OP is attributing this to being a UA problem since ORD is "home of UA". Though the same could be said about AA.

UA (and AA) have little interest in the restaurant situation in T5, as their passengers never interact with them since the only time a UA passenger is in T5 is an international arrival which doesn't have access to the restaurants in the departure area.

I suspect the situation will improve when DL moves over in a couple months as there will be a more consistent passenger volume that would support keeping these restaurants making sure they have staff and are open (and DL would probably make some noise making sure there are facilities open to service their passengers with their flight schedule)