Sure they can do this without anyone getting sued, but they can still face consequences for doing it (like people not going to see the Rockettes).
People like the OP seem to forget that legality is not the ultimate moral code.
I’m just saying people who lean on “the law is this, they are in the right” ignore a major part of society and commerce to their own detriment.
The idea that the law is just a bunch of words and your job is to advocate for them to change if it improves your life in any way is not a great guiding principle.
That's not what happened though. They sold admission to a person and then rejected it because that person works for a firm that has an open case against another company that they're conglomerated with.
It smells like retaliation to me, but I guess it will come down to what the courts decide.
It can be a good thing while we regularly and objectively evaluate a principle's worth. We humans have a history of allowing principles to obtain rigidity and the diminished outcomes that follow. We also tend to allow principle creep w/o sufficient examination.