Hi Eddy
Fair point & yes the driveshaft will come away from the subframe without removing the hub nut ( Although any ABS may have something to say about that )
My point is, we are dealing with a donor car that is 20-25 year's old & potentialy 150,000 miles on the clock.
Let's say that you take the easy route and remove the shafts/hubs as a single unit ..... Great idea right up to the point you notice any of the following .... Rough/worn hub bearing, play in a CV joint or split CV boots
You are then left with the task of trying to udo the rear hub nut .... You'll then be in the not very exclusive club of the many folk who have uttered the words " If only I had loosened those nuts before I removed it from the car "
Take it from me, slacken those hub nuts off half a turn before you strip the donor & no, you will not dammage the bearings !!??
I can think of a dozen reasons to slacken the hub nuts & none for not doing so