With a few rare exceptions... I doubt very many people at all got promoted on that trip. You have a single ship, with a single command structure and promoting people is just gonna screw with that. There's even less of a need for promoting people as you take casualties for the most part.
Tuvok got promoted, but that was mainly to cement him as third in command more than anything else. Tom lost rank, the Voyager hierarchy wasn't effected... at all. He got it back, and the only consequence was Harry feeling deprived.
Now after Endgame, I'm sure there were promotions across the board. Pity they decided to fade to black rather than show an actual resolution.