I'm pretty certain they won't completely give up on PSO2 because it wouldn't make any sense to keep both together otherwise. I think they will just slow down the updates, then make the NGS scratches (that we are 99% sure are coming) apply to both versions, keep seasonal content rotation, and probably will make a few quests linking both games together (DOLLS quest in PSO2 and maybe old PSO2 enemy spawns that aren't rappies xD). As usual time will tell still.