No series revival can ever succeed by relying on the pre-existing fanbase alone, because it's just not large enough. Pre-existing fans have an exaggerated impression of their own importance. Even for the original series, the serious fans would've been only a percentage of the audience, with the rest being more casual viewers; and the longer the series has been off the air, the more the fanbase would have shrunk from attrition. So the core fanbase for any franchise is never going to be large enough by itself to make a new show successful in the ratings. That's the whole reason revivals are made -- to introduce the series to a new audience of casual viewers and new-made fans. To grow the audience, not just pander to the one that's already there.
So there's no reason a continuation of an existing universe can't appeal to new viewers. That's the goal of any spinoff or sequel series as a matter of course. The key is not to rely solely on continuity porn, but to create something interesting enough to have appeal on its own while still fitting into the continuity that came before.
