Frank Pearce, Chris Sigaty, Jay Patel, Alan Dabiri, Bob Fitch, Monte Krol, Collin Murray, Mike Heiberg, Robert Bridenbecker, Dave Berggren, Samwise Didier, Eric Henze, Allen Adham, Scott Mercer, Matthew Morris, Jeff Chamberlain, James McCoy, Seth Thompson, Glenn Stafford, Derek Duke, Jason Hayes, Eric Dodds, Jason Hutchins(?), Michael Chu, Justin Parker(?), Kaeo Milker, Ed Hanes(?), Geoff Goodman, Shahram Dabiri, John Lagrave.
These are just a few of the credited people for Warcraft 3 who all still work at Blizzard. Ones with a (?) are ones I couldn’t find a confirmation for in more recent times (within the last two years).
Granted, not all of them are on the Classic Games team but it’s hard not to imagine that they’re accessible enough to consult for Reforged.