On a storytelling level, the fate of the Ghost Host is actually very important in establishing a sinister and threatening edge. And even when we discover, later in the ride, that the spirits are mostly just partying, there is still a straight-faced macabre thread running through it that begins with that pre-show.
Of course, as we've seen before, narrative coherence isn't much of a priority for Disney when they tinker with their classic attractions (starting all the way back with the extended queue at MK's Mansion, which features some light ghostly goings-on way before that stuff should be experienced by us within the story of the attraction).
So I expect, if they do replace that element in the stretching room, it will be with something much more overtly comedic and silly, done with little thought about what that does to the overall attraction.