His latest blog contain a big hint that the Montana will be among the ships in the new set. It's already been figured out by sharp-eyed bloggers that an O-class German battlecruiser will be in the set, so we have at least two hypothetical ships in the set already. This will bring complaints from the usual quarters, of course, but I don't have any problem with hypothetical ships myself. One of the nice things about naval wagrames is the ability to test out interesting what-ifs in any case.
There simply aren't that many naval battles in history to be restricted to historical match-ups. Naval battles are much more rare than land battles for a host of reasons, so hypothetical s have always been part of the landscape for naval gamers. I don't see an awful lot of difference between a game that allows a duel between the Bismark and the Iowa and one that allows a duel between the Friedrich der Grosse and the Montana. Both were impossible unless history played out quite differently.
I do agree that RB's plans need to make sure that the key historical pieces make it to collectors before the line ends, but we're in pretty good shape on that score. I think the only gaping hole in the line at this point is the Hiryu, which is a mandatory ship given its participation in Pearl Harbor and Midway.