To be honest that makes a lot of sense, particularly given Mitsubishi's track record for changing things in increments and the fact that the FQ400 models proved fairly conclusively that stepping up from the very well sized 16G gave more power at the expense of extra turbo lag. I really don't see Mitsubishi going more than marginally bigger with these turbos in a production model all the time that they retain the 2.0 litre, 8.8:1 CR formula they have used for the last 8 years.
By the way, I take it that that Revshift 2G manifold would still bolt up to a 1G head, but is it going to fit in the rather more cramped VR4 engine bay?