User blog comment:Argorrath/Treyarch releases a BO2 teaser video called "Origins" for DLC 4/@comment-1263839-20130808151749/@comment-3967954-20130808153137

Agreed. I'm willing to bet Treyarch reused Reznov and Mason's models (albiet modified quite a bit), since they seem to like reusing stuff.

As for the identities of these guys? If it were the original characters, I think Treyarch would make it more obvious. These guys look completely different (although I'm not going to rule out Richtofen quite yet - he's probably old enough to fit the setting). Logically, they can't be younger versions of the original crew because they'd be much too young (again, bar Richtofen) and these new guys don't look all that young themselves, and to the people saying "oh but they time-travelled" - do the letters look like they were written by time travellers? There's no mention of the previous events in the storyline anywhere.