Lot of things make this a crack pairing for me. First, there's the whole idea of taking Robinson's Don't Cry for Me, Justice/Argentina as a serious JLA title. Which I can't. It's just laughably bad.
Secondly, it's been made clear in Kingdom Come (out of continuity, I know) and Power of Shazam (where the series left off) that it was Mary and Freddy as the OTP. Which makes it all the more odd that he's macking on Supergirl who was still twisting Mary's neck even after Freddy told her to stop in Final Crisis (never followed up on or mentioned again).
Never mind the fact that Freddy as Captain Marvel/Shazam/whatever DC is calling today will eventually go the way of the dodo when Billy comes back as Cap (as we all know he will at some point).
What bugs me the most is I can not take this version of Freddy Freeman seriously - because DC obviously doesn't. He went from a slim teen (and he was historically the only Marvel who looked his age) with a bouffant Elvis hairdo into a bulky hunky long-haired romance novel cover model 20-something-adult in the historical red Cap suit. Anyone who didn't read "Trials" might think this is Billy/Cap kissing Supergirl (what would Stargirl say!) because apparently DC thinks the two characters are interchangeable.