The T/S lenses would have to have tilt and shift sensors with tilt angle and direction, shift amount and direction embedded in the EXIF in addition to the normal info about lens corrections. The correction calculations would be massively more complicated than for normal lenses. When the T/S lenses were designed nobody thought about this. Maybe new models will have it in the future.
Yes - precisely.
The present TS lenses are not weatherproof by any stretch of the imagination (think of the sliding joints).
If sensors were added, they'd have to be protected would they not?
This would seem to very much complicate matters and increase the cost of the lens significantly. How many other great TS lenses can you count on one finger?