So with Dragon Ball FighterZ coming out at the end of next month, it would seem we have at least 2 big V-Jump reveals left (not counting any potential Jump Festa trailer, since we already know the game will be there.) Given how we've gotten 2 to 4 characters in these, it would seem we have from 4 to 8 characters left to round up the full main roster.
I'm betting on this month's character reveals being focused on Super era characters, as in the last month we explicitly got a "Buu arc" reveal. Those characters in my understanding would be Beerus and Hit (very possibly leaked by Jump last month, Hit was the more dubious one but it seems more likely now that we have a Ginyu icon to compare and found out they're very different) alongside Fused Zamasu (though we could get just Rose). My main reasoning for Zamasu being that we got the Goku Black era Bad Future stage in the game, however, the story itself uses the bad future so It's possible Zamasu or Black don't show up till the DLC wave. There's also the possibility of Vegito showing up here. But, yeah, that's my "bold" prediction for this month's wave of characters.
As for the January V-Jump, I got no idea. I can see them revealing Android 21 as a playable character (though I think that might be it's own separate reveal like Trunks was), maybe some movie/OVA characters or, hell, the final reveal could be this month. I don't see any Tournament of Power or GT era characters since those scream DLC fodder, same goes for a couple of movie characters.