AWD to FWD fuse

[Brian]

I was told this by a certified Subaru tech regarding AWD SVX's:

"There is a fuse spot under the hood in the box that if you put a 20 amp fuse in it it will turn off the rear wheels for summer driving."

Is this right?
If it is, would running the car like that be easier on the transmission (as the FWD SVX's are supposed to be easier on their transmissions than the AWD SVX's)? Or, since we're talking about a car that is designed to be AWD, would this just cause the transmission to deteriorate faster?