I don't think you have any idea just how massive FNAF is. The fan base is HUGE and definitely bigger than Terrifier's or Scream's. Let's take a look at the box office numbers for the franchises. The most Terrifier made was $87M. The most Scream ever made for a singular film was $173M for the first film. The FNAF film made $297M. Apart from that, couple in the massive reputation the franchise has made for itself with the dozen or so games it's had and the massive fan base, not only within adults, but within kids as well and yeah, it's a big franchise. Scream has been around for a while and is probably more 'iconic' than FNAF but as for which has a bigger fanbase at the moment, FNAF definitely takes the cake. Plus, just look at the comments on announcement posts from last year on HHN's Instagram or Twitter. Most commenter's are just talking about FNAF left and right more than any other property. Point is, it's BIG and it's probably going to rack up the longest lines if it does make it to the event this year.