All the rules are up on the website, at least in the UK. Good to hear they're on the app, too.
Crypt Horrors look the same to me, but as mentioned they get a hero version. Model-wise, it's a crypt horror with a vargheist head. I already modeled my horror champ with a vargheist head and one vargheist wing, so I guess I'll just call him that. Instead of all his attacks being 2 damage, with 3 damage on sixes to hit, like normal horrors, he just has three attacks that are three damage always and two that are one damage always. Kind of a wash there. Still regens a wound a turn, and re-rolls hits for nearby ghoul kings, but his big ability is that you roll 6 dice, and for every 5+ you add a model to a nearby crypt horror unit of your choice. Very impressive. Make sure you keep him out of los, he's going to be a high priority target.
The Flayers are crypt horrors with vargheist wings (or, alternatively, vargheists with crypt horror backs and heads). I know several players out there already assembled their vargheists with crypt horror backs because they didn't like the fur anyway. they're fast, they fly, 1 damage attacks with rend -1, and have the spirit hosts 'mortal wound on 6 to hit instead of normal damage' ability. They each have a mini terrorgheist scream at d6+1. Only even capable of harming leadership 6 or less units as a result, but it's something.
The Flayers have their own hero version, modeled as the vargheist champ (the back with two extra little wings) but with the ghoul champ's head (the one with the big ring through his neck). I'm sure we can come up with better conversions. He has a d3 damage breath attack instead of the mini scream, 2 damage melee attacks (including 2 mortal wounds on a six to hit), and the same 'roll 6 dice, add a model to a nearby unit for every 5+' ability as the horror hero, but for flayers instead. An impressive hero, rules wise, though again you'll need to hide him until you're ready to charge, which may be rather difficult.
Additionally, the 'Varghulf' is now a 'Varghulf Courtier' hero. I'm not sure if this replaces the original Varghulf, or is in addition to it. The varghulf courtier is fast, flies, has 5 attacks (7 if within 3" of at least 10 enemy models after piling in) - one at d3 damage w/ -2 rend and the rest at 2 damage and -1. It re-rolls to hit if a friendly flesh-eater courts wizard cast a spell w/in 18 inches of it that turn, heals d3 wounds at the end of any combat phase in which it slew any enemy models. Most of all, it has its own version of the model summoning rule of the flayer and horror heroes, rolling 6 dice in your hero phase and for every 2+ you add a model to a ghoul unit.
Overall, the new Courtier heroes seem to be there to give ghoul armies that undead recursion theme that is otherwise missing due to the lack of banners in the army.
All in all, I like the new units rules-wise, but the lack of actual new models (a dual kit horror/flamer hero and a plastic vargheist at least would have been nice) is a little discouraging. Still, all in all not a bad lot, and the Ghoul Host army box is a solid discount and looks like a pretty playable army out of the gate.
Oh, also there's a change to the Ghoul King on Terrorgheist. It regends d3 wounds every turn - maybe it did that before, I forget? But it also has a new command ability, which summons 3 crypt horrors or flayers anywhere on the table more than 9" from an enemy unit, and they cannot move in the following movement phase.