I don't know anything for sure, and not a huge fan of the Weeknd (does it make me cool if I call him Abel instead?) so my opinions surely aren't anything that should be taken seriously...but my takes are the following:
Orlando HATES repeat houses, even super popular IPs like Stranger Things and The Walking Dead. They waited a long time for a return to Slaughter Sinema so I wouldn't count out his return in the future, but seems too soon for Orlando. Hollywood has no issues with repeats. Case in point, people here are already (rightfully) complaining about Blumhouse being a rehash/recycled zone.
Has he released any new music since the last house? Granted, Dawn FM hasn't been covered at the Orlando event, but has anything new come out? I liken this as to why Stranger Things and The Last of Us aren't back this year with plenty of meat still on the bones of those IPs in terms of S4 and the first two video games stuff not yet covered.
From what I understand, he's not the most popular person right now. His HBO show was a dumpster fire with all kinds of allegations of him causing problems.
Doesn't he make outlandish demands for his cooperation with his works? With the rumors that's what scuttled FNAF, with Epic construction being the #1 Orlando priority, maybe it just wasn't financially sound to pay for his rights this year.