I would disagree with that... The Bladegheist revenants are now effectively filling a similar role as the dreadscythe harridans, only with a worse warscroll compared to the one very recently updated. That makes them a dud as well (so far of course).
And yeah, we'll have to wait and see what those allegiance abilities are of course. The only thing to go on for now, are the updated or new warscrolls. And barring the myrmourn banshees, they don't paint a pretty pictures sadly. The Bladegheist have been straight up nerfed in their warscroll... no doubt about that right there... And they are "in competition" with other similar infantry from an internal balance point.