An important part of responsibly managing an intellectual property is knowing when to show restraint. Any IP is capable of suffering from oversaturation if it is utilized carelessly, rather than strategically. While the Marvel Cinematic Universe was the undisputed biggest media empire on the planet for a long time, a combination of inconsistent quality, and too many releases for fans to keep up with, has caused at least somewhat of a decline more recently.
I do firmly believe we will continue to see more Universal Monsters houses in the coming years, but now seems like the perfect time to give it a break at the event, especially as they as utilizing it in other big ways. Universal and the whole horror media industry have a lot to offer for the event, so it could be exciting to see them mix it up a bit.