No idea if this was supposed to be for Alton originally. The largest evidence for me that it may have been are the public surveys, shared on this forum, that showed Minecraft proposal for Alton Towers before a CWOA one.
I think it may have even shown the location of the potential Minecraft area as near Dungeon etc. I believe the actual pictures/scans of the survey were taken down at the request of the owner.
Common sense suggests it’s completely plausible that a switch happened, but we are unlikely to find out for certain anytime soon.
Also on the £Xx million investment front. They are likely including the licensing fee in that when trying to get to the largest number for a press release.