It's definitely a cart to transport a coffin, and not a coach to transport riders. I personally don't mind the change, though, and think the overall model is just amazing.
Having picked up the full battletome and looked at the formations... not only are there no bodyguard type formations for the special characters, Olynder and Kurdos don't have any formations they can be included in at all, and the formation you can take Reikenor in seems a much better fit for a regular knight of shrouds, both mechanically and aesthetically, though it does provide a modicum of extra protection, so that's something.
So that again leaves all three special characters with only 7 wounds, and only a 6+ death save to protect them from mortal wounds. As cool as the abilities on Olynder and Kurdos are, they just don't seem durable enough to justify their points cost to me. It feels like a stiff breeze will see them off the table. Nighthaunt deep strike rules, particularly combined with some chronomatic cogs and maybe a deathrider formation, might be enough to tie up enemy ranged units before they have a chance to strike at them, though? And I suppose you could keep them in reserve until things are safe for them to show up. Kurdos in particular I don't think really needs to be on the table in your first hero phase, so maybe things aren't as bad for them as my gut's telling me at first glance, but all in all I'm pretty skeptical.
At 180 points, and a decent mix of melee and magical abilities, Reikenor's a bit easier for me to stomach.
I am a little frustrated about how few command abilities there are in the army. Only Olynder and the Knights of Shrouds have their own CAs. None of the many other heroes do, including the other special characters. The faction does have a general use CA for repositioning, but given the restriction on being close to enemy models when most likely nighthaunt generals seem to want to be pretty close in, and the deep strike ability to put units where you want them to begin with, I'm not sure how useful that is. After all the hype on command abilities going into 2e, it's a bit annoying that the first big faction release for 2e doesn't have more relevant toys to play with in that regard. Oh, well. The charge re-roll is better for nighthaunts than most other factions anyway, so most of your CPs were probably going there anyway.