Contracting businesses can and do discriminate all the time. Do you understand how contracts work? A business offers a contract because they perceive that the value received from that contract will exceed the cost of that contract. If at any time their assessment changes, they have the right to terminate that contract provided that such a termination agreement is included. You don’t get to pick and choose what reasons are valid and which are not. You aren’t the one assuming the risk here. A&E is, so the decision remains theirs alone.
It’s against the law to discriminate against a provider because of race, religion, gender, etc. And scotus has, for all practical purposes, added sexual orientation to that.
Let P&G, for example, decide against XYZ corporation’s bid on the basis of their race. See how fast they get taken to the cleaners.