Adding vintage classes of subs and vessels to DW is possible if the devs want to. Truth is, their time is better spent working on contemporary models.
If and when all other desires are satisfied, I, too, would like to see a couple retro models added for some "ghost ship" type scenarios. Maybe a reverse "Final Countdown"?
Hey, if someone could somehow port Enigma: Rising Tide models into DW, an old fanboy desire would be fulfilled.