A control city isn't useful if motorists coming from far away and unfamiliar with the area don't recognize it. And it's explicitly stated in the MUTCD that guide signage is supposed to prioritize unfamiliar motorists not from the area.
PennDOT disagrees
But seriously, seeing NYC as a control city on I-80 EB in Ohio (which is a perfect control city imo) then various small cities in PA until close to the NJ border doesn’t really help unfamiliar motorists.
I get the desire to give unfamiliar motorists useful information, that is after all the benefit of a well signed grid.
But there is always a balance to be struck here. I don't see the point in catering to the lowest common denominator, and unfortunately the geography knowledge of the average person in this country is sadly lacking.
Someone that does not know how many states there are is also unlikely to have heard of cities like Toledo Ohio or Pittsburgh PA if they are not from the area.
So it seems reasonable to give the best available control city, but being universally recognized cannot be a criteria.
I am of the opinion that at least one control city should be posted for every state the road passes through, that way motorists know what state lies ahead which is of some value as well.