While I agree with the latter part of your statement, I don't think this will really do much to alleviate pressure at The Club (TM). While I don't know this, I would opine that most people there are Priority Pass cardholders and not Amex Plat/Cent holders that would have access to the objectively better SkyClubs when flying Delta. I realize there is a small group of Amex cardholders transiting ATL that aren't flying DL but it's probably a rounding error for purposes of this discussion.