If I had to predict, given how KH1.5 and 2.5's release dates were in the late Q3 and Q4 of 2013 and 14, it's safe to assume that 2.8 will be in the same region as well.
Nomura even said that they are able to make an HD version of DDD, but since it's a single game, they think it would be weird to release the HD version as a single game.