More thoughts;
I would guess we are getting a new mount (fingers crossed). The small picture in the warcry shows frills, but it seems that they are positionned behind a shield. If my interpretation of the blurry pic is right, then those frills couldn’t be attached tohe neck of the mount, its just not at the right place. So it may just be a decoration or feature of the rider, not the mount. It shows up on the leader page of warcry, so it could technically be a new leader on mount with no troop equivalent, but I feel that is unlikely.
The second page of leaks, opposite the sybarite troopers shown, shows the same ranged attack of 3-15” and a melee weapon on an unseen unit entitled”Bliss”(giver?). Is Blissgiver already a slaanesh unit?
It feels unnecessary on a unit that won’t add much to the army list, whereas a more anvilish unit would have been able to shake listbuilding more.