It’s not that vampires don’t encounter other supernatural creatures.  It’s that with very, very rare exceptions, Kindred and these creatures give each other a wide berth.  The Beast recognises them as highly dangerous predators in their own right, and instinct keeps most vampires away – and for their part, the other supernatural creatures presumably don’t want to go near something that might try to eat them.

As a general rule, Kindred know which bars they might run into other predators in, and avoid them, sort of thing. (And indeed, in London, there are areas that Prince Caddell has directly told the court “That district belongs to Something Else.  Go there at your peril.”  We haven’t bothered to enumerate exactly where, because it’s not directly relevant in the scope of the game.)

But still, in London, it’s not uncommon, once or twice a year, to feel a presence of Something Dangerous (the Beast doesn’t distinguish enough to know what that thing is without effort) at the end of the street, it’s just that instinct has Kindred turning to walk the other way, rather than to seek it out and talk to it.  Rare Kindred might have chatted to Something In A Bar That One Time, but it’s unlikely they’d have 100% known what the creature was, and it would have been a careful and polite chat about nothing much.

Lastly, and specifically: this setting does not feature werewolves, at all.

The night holds ghosts and changelings and mages, and other, weirder, things, but no vampire anyone knows has ever claimed to have encountered a werewolf, and while some vampires might reasonably think that given all the other supernatural legends seem to have some basis in truth, so maybe there are werewolves out there, there’s absolutely no basis to believe in them beyond that.

(At least one of the refs is very tired of werewolves featuring in Vampire games, and thinks they make bad antagonists for many reasons, so we’re just opting to not mention them at any point in this setting – we’re not going to say they exist, we’re not going say they don’t, they’re just 100% irrelevant and Not Appearing In This Game.)