The best advice is to wait and see what's offered as the merger deal progresses. The variables include not only the closing date of the deal, but when the two carriers will move to a Single Operating Certificate, when *A will formally end for US, when the separate UA-US Club deal ends, when your current Club membership ends and so on.
What the Club agent told you is true in the long-term, but the Agent has no idea what that term is and you can have no idea what will and won't work downstream.
The entire issue of whether or not the AA deal is a "debacle" is completely irrelevant to the Club access issue. As with all changes, it will be a great thing for some and terrible for others.