Originally Posted by kevin
But maybe she would have been reassigned to something other than deep space assignments.
You mean like taking cadets on training cruises?
The thing about Unification is that was a scrap yard. That's different than a mothball fleet which is properly called a reserve fleet. The ships are stored and are maintained in sufficient working order so that they can be reactivated in emergency situations. One example of such a place is the Puget Sound Naval Yard in Bremerton, Washington. Had the Enterprise been destined for a reserve fleet upon decommissioning, she probably would have been sent to drydock for repairs and a small refit before being sent off to the reserve fleet.
A more accurate example would be the case of the Defiant prototype in DS9 which was pretty much placed in storage after the project was essentially put on hold. Another example would be the USS Sovereign as described in the manual for the Bridge Commander computer game although the back story for the Sovereign has yet to be confirmed on screen and in all likelihood will never be fleshed out on screen.
There is one piece of onscreen evidence to indicate the possible existence of a reserve fleet in Star Fleet. During the initial Star Fleet briefing in Star Trek 6, there was one flag officer that asked if the result of the proposed peace talks would result in "mothballing the star fleet". Now after Star Trek 6, the Enterprise-A was in all likelihood decommissioned and immediately stricken from the Star Fleet registry instead of being placed in a mothball fleet. In which case she could have been scrapped or placed in a museum. Or if she was to have gone to mothballs instead of being stricken, then it's possible that she would have been given a new name and hull number; however given the unique nature of the Enterprise hull number, the number could just as easily been kept the same along with the name. This would have been done in anticipation of the Enterprise-B, as having two ships of the same name in the registry can cause confusion. Just having two ships of similar names tends to cause confusion as was the case of the USS Hamilton and USS Alexander Hamilton in WWII. When the US entered the war, all Coast Guard assets were transferred to the Navy. This included the cutter, Alexander Hamilton which was named after the first secretary of the US treasury. The Navy already had a destroyer named after LT. Archibald Hamilton. Both ships however were usually referred to as Hamilton for short. As a result, there was an incident where orders were sent to the wrong ship resulting in the Coast Guard Cutter, Alexander Hamilton, begin sent out into the North Atlantic instead of the destroyer. After realizing the error, the Navy sent out a fleet wide communication stating that in all future communications, the cutter would be called Alexander Hamilton and the destroyer would be called Hamilton.
Edit: going back to the whole question of a refit. Strictly speaking, refit means to fit out or supply again; to obtain repairs or refresh supplies or equipment. Anytime a ship comes into port, it's going to get a refit. The term refit that Star Trek fans use colloquially when referring to the transformation of the Enterprise from TOS to TMP really shouldn't be called a refit. It's a modernization. It's just like when the battleships were recommissioned in the 1980s and had electronic warfare suites installed as well as other systems, that was referred to as a modernization and not simply a refit. Upgrade is also an appropriate term, though modernization tends to fit better in terms of the scale at which the Enterprise was upgraded.