Okay… I see this “launch to 88 miles an hour” thing a lot (and not just you, so please don’t take this response personally… I just had the time to do the math today).
To launch from a dead stop up to 88 miles, in two seconds, would be an acceleration of 65 ft/s, or 19.66 m/s. That would be the second quickest launch in the world. Universal would love a record breaker, but probably not like that.
A launch that quick would also require about 130ft of track. That distance is important, because of the whole point of a launch like that is to enjoy what happens after.
The second Velocicoaster launch is about 260ft, and typically uses momentum at that distance. The Starfall/Stardust racer launch is about the same. The Fast and Furious building is about 370 feet long. So, basically, a 88 mph launch, at a record-breaking quickness, basically becomes a stat coaster. It wouldn’t fit Universal’s MO.
So, let’s slow that acceleration down to 3 seconds, (13-ish m/s). Still pretty darn quick, but more in line with Universal’s MO. However, that requires more track length. Now, it needs a launch a little over 290 ft. That is longer than the VC and SR launch lengths, and basically takes up the entirety of FF, before any elements like turns are added.
The only viable location, in this structure, is replacing Rip Ride Rocket. Not a horrible idea, though it would be very out of place thematically.
Basically, don’t expect a BttF coaster. Doing a BttF that DOESN’T go up to 88mph is pointless. A dark ride or simulator (which… yeah… we’ve seen) is logistically the better more for Universal… that’s why we won’t see it.