I dunno. I think contemporary audiences don't have any idea who anyone other than Dracula and maybe Dr. Jekyll are. Look at how many articles had to explain who Renfield was when that trailer came out recently.
If anything, I think the Dark Universe is a great example of not going with a franchise that someone loved as a kid, without realizing that today's young people don't have any warm and fuzzy feelings toward it. See also Alan Quartermain, the Phantom, pretty much every Tarzan movie in color, John Carter, etc.
The fact that you have the rights to something and loved it 40 or more years ago, does not mean that'll translate into market success.
This will pain a lot of people posting on this site, but you have a better chance of seeing a Herobrine movie be a giant commercial success than you do a new Wolfman or Drizz't movie.
(Everyone just back from Google: I know, it seems crazy, but Herobrine is 100% a well-known character amongst the young folks, many of whom grew up believing a ton of urban legends around him. But unlike Slender Man, Hollywood hasn't put out any half-assed movies with him yet.)