A couple thoughts:
Wasn't Pixie Hollow to have included a dark ride and a version of "Mater's Junkyard Jamboree"?
With the removal of SWA and no rumors of the MJJ spinner making it into the new plans, FL is indeed going to have one less ride than it would have in the original FL plans.
Or is it possible the MJJ spinner could show up in Dumbo's Circus to fill in that area?
Is it also possible that the "Mystery Ride" will have the same or better capacity than SWA, MJJ, and the PH dark ride had combined? (At the end of the day, it's all about capacity over quantity)
Another point to consider: Staggs said the new budget will be only slightly higher than the original.
That means the "Mystery Ride" will at least be the same cost as the orginal M&Gs.
Any other money for it would have to come from the PH dark ride (if it truly existed) and the MJJ spinner (if it has been cancelled).
Of course, there would be some minor cost savings on the "Mystery Ride" if the old sets and figures from SWA were re-used in, say, a Seven Dwarves Mine setting (which, like the "Tangled" title change, could set this apart from being strictly a "princess" thing)
But Lee and others have apparently not heard that Seven Dwarves Mine is coming (and was it even designed for another park, as others have suggested the Mystery Ride is?
)
So one last (crazy) possibility for funding: could SWA be "sold" and relocated to another Disney park, with proceeds going to the Mystery Ride (or would the track, vehicles, ride controls, sets, and figures be fairly worthless and cheaper to build from scratch?)