Yeah, I genuinely don't get this talking point.
For one, there's still a ton of horror releasing in 2024 (see: everyone's fantasy wish lists for HHN33). For another, the follow ups to recent HHN IPs were never dropping in 2024, even pre-strike (i.e. ST5, TLOU2 M3GAN 2, Exorcist Deceiver, Black Phone 2, and so on.). Blumhouse is still going to have multiple releases as always, Weeknd is still on track for his new/final album if that collab happens again, several big IPs for 2024 have had involvement at the event in the past, FNAF still exists, older movies/franchises still exist, etc. Maybe I've missed some big horror delays or something, but the whole thing feels overblown.