Going to make a guess as to what will have the longest lines:
Weeknd - Sound stage maze, main attraction on the lower lot, after 7:30pm, will just be jammed until closing.
Halloween - Main attraction on the Curious George section, will probably taper off around 11pm-12am like this section usually does, but will be 2+ hours for most of the night
Terror Tram - Everyone seems to be excited about Us and NOPE. Terror Tram usually sports a lengthy wait, but I think these IPs are going to drive it up a bit more than normal.
Killer Klownz - By being on the lower lot near Weeknd, plus it's popularity, and how popular it was in 2019, I think this will be a little higher than average.
Scarecrow - Just by being next to Halloween, I think Scarecrow will get the leftovers. Also really depends on word of mouth if it can beat Halloween.
Blumhouse - People like the Black Phone, so of the upper lot mazes, I think this will get the most wait times. But I think the upper lot in general probably won't be too bad this year.
Hotel - I had this dead last but I remembered there's a pre-show. I suspect that will hold things up a bit. Unfortunately, the name isn't all that intriguing, so it won't be exactly alluring to guests. I honestly think this will just be a surprise for most people either wandering into the line or finding out it exists before they exit.
La Llorona - This location never sports hefty wait times, but La Llorona is such a legendary icon, plus it's been 10 years since she's been at the event. My guess is this will have a steady flow, maybe not as little as years before, but at least it won't be a dead zone.