I found an art concept posted online, for this new attraction.
And it looks like the haunted swing ride is a Bye-Bye, too?
Or as it was known...le Palais du génie
The haunted mansion will remain in the park, it's located near playland at the other side of Radja River, you can't see it on that concept art, however the area near the haunted mansion will (i think either this or next year) get a big update with a new small kid-coaster running over the path, between playland and the lake. (see attached photo)
btw, a few months ago i threw this togheter, its all the plants overlayed with the excisting sattelite pictures. https://imgur.com/a/5A9kF
*edit*, the new coaster won't run over the path, the main pathway will be moved towards playland so that it's more integrated into the park and not like some side area. Great move from Walibi! really digging their future plans.