This is why people in the publishing world often advise writers seeking traditional publication not to write to trends. Because unfortunately, the time between a manuscript being sold and ending up on the shelves often takes years, so by the time a writer sees a trend, writes it, finds representation, gets it sold and the release date arrives, that trend is way long gone.
That doesn’t mean, however, that if you adore YA Paranormal or Dystopia (or any dead genre, for that matter), that you shouldn’t write it.
These days, you can write whatever you want to write. For example, gothics romances were considered "dead" for years, but I've seen several authors turn their gothics into hot sellers in ebooks.
If you're a fan of old-school gothics, you'll be pleased that Victoria Holt is now available on your Kindle.