SIN/MNL are likely on the chopping block if this comes through and they don’t separately receive slots - as you say, I doubt they would be eligible for the DOT allocation. I imagine those two remaining hub routes would probably go to ICN, SEA, or get cut entirely in favor of MU/KE connections.

SEA-SIN seems unlikely-ish as long as SQ is in town, unless DL feels like picking a fight, but I’m not even sure they could get fifth freedom rights from South Korea. It’s not out of the question - KE does have authority for LAX-GRU, so there’s a reciprocity argument to be made on that end, at least. Seems likelier than PVG, at least. Maybe DTW-SIN, although that’s pushing the boundaries of route length...