With regard to Scarecrow 2: I never actually heard it rumored. It’s been heavily speculated as returning in some capacity because marketing used a Scarecrow image in one of its first post about HHN 30, stating the year would feature reimagined things from the past. Personally, I’ve held the belief that if Scarecrow returns, a zone in Central Park makes more sense than another house. But, again, it’s not a rumor. It’s speculative.
Regarding 20/21:
Fear was far better than Luck. While both were pretty boring, at least Fear wasn’t bad. And his zone was light years better than Luck’s. The streets in 20, across the board were better: Saws and Steam, Esqueleto Muerte, and Zombie Gras were all remarkably creative, effective and consistent. Even its weakest zone that year (The Coven), was better than most of 21’s (I’d rank it above Canyon, Luck, and of course Nightmaze).
Houses are going to be a little more equal, and I’ll admit I have some personal animosity towards two fan favorites from 21 (Bloodengutz and Nightingales). I hate them both, and rank them in my bottom third. The In-Between was a top-tier house, and The Forsaken turned into something that worked. But The Thing and Nevermore were somewhat and Winter’s Night was a lot of style over substance (there’s a reason a Doctor Who Easter egg is the most memorable part of the house).
HHN 20, with Catacombs and Havoc, had two all-timers, unique and satisfying fan-service (Orfanage, Legendary Truth, and Hallow’d Past), and narrative twists with the first “integrated” house and zone with Zombiegeddon. Its two weakest houses, Hades and Echoes of Shadybrook, were more forgettable and bad. Throw in the fact that 20 is one of the few years with no IP presence at all, and it’s something unique.
HHN20 beats out 21 on pure consistency.