If I didn't know the history of the movie franchise, I would have said that the -A was the refit, considering the shuttle bay was almost identical in shape and design to the original, vs the cavernous shared shuttle/cargo space in the TMP version
I always considered the “A” a renamed older ship. Not enough time for it to be a fresh build with the name Enterprise. If it was a new build, that would definitely point to no plans to retire the class.
I legit like them better here than I do in DSC. Far as I'm concerned, DSC is the one that got it wrong.
They probably only name the ships once they're completed and ready to enter the service. So before it was Enterprise, it was an unnamed hull under construction for a while. And I don't think the talk about retiring the Enterprise in any of the movies directly implied that whole class would be retired then. However, it was clear that it was kinda outdated and as we know that they were no longer in service during TNG, they must have been retired at some point before that, sometime in the early 24th century most likely. Also, Connies were the premium supership for a while, and there most likely never were many of them. Only twelve during TOS. So it is quite possible that there wasn't a decision to retire the whole class, they merely stopped building them once they were confident that Excelsior could work as a replacement, and over time the individual remaining Connies were either destroyed, damaged too badly or otherwise worn out.
In my opinion, introducing the 1701-A was a stupid plot twist, completely retconning the idea that the Constitutions were being sacked in lieu of the newer Excelsior class. It was a metaphor for Kirk feeling old and obsolete. What they should have done is rechristen the Excelsior as the Enterprise A. All the "system failure" jokes in V would have still been useable. Then there would have been no need for the Enterprise B in Generations -- it could have been the A, as Kirk indicates in his final TUC log entry: " This ship and her history will shortly become the care of another crew. To them and their posterity will we commit our future."
No where was the idea they were being sacked introduced. The Enterprise was being retired, her "day was over". That the entire class was being decommissioned is fanon. It definitely doesn't line up with "Mr. Scott's Guide to the Enterprise" which was the official publication on the ship after Star Trek IV.
(Pulls Mr. Scott's Guide off the shelf): This "official" publication says the 1701-A was a re-christened USS Ti Ho, a new build (not a refit) that hosted transwarp drive (Appendix, page 112). Also, it lists the launch date as 2217, which clearly doesn't mesh with the currently accepted dates for the series (yes, I know it was published before TNG gave us an accurate calendar year). I'll choose to ignore this non-canon source in favor of the strongly hinted at fact that the Constitutions were being phased out in lieu of the Excelsiors, which is supported by the lack of one and plethora of the other in TNG.
Honestly, I think Star Fleet was actually trying their hardest to "retire" Kirk and just used the Enterprise as an excuse.
They opted not to refit the original Enterprise, which went out in a blaze of glory and the A was turned over to a new crew at least until the B was launched.
Having the Enterprise-A be an almost identical Constitution-class starship was also comforting for the audience and a lot less jarring than sticking our heroes on the bridge of a class of ship that just one movie before had been chasing down the previous Enterprise and commanded by a haughty, self-righteous jackass with too much faith in the technology aboard his own starship. The 1701-A being from the same class and - from the outside at least - indistinguishable from the previous Enterprise was good for the audience, economical for merchandising(if there would be any)and good for the special effects artists and modelers who just had to slap an "A" suffix on the preceding Enterprise's shooting models and go from there.
I recall from DVD commentaries/extras that the Excelsior was deliberately designed to be an unlikeable adversary ship, so I doubt it was ever intended to become the hero ship.
I remember it quickly earned the nickname "Pregnant Guppy" when publicity stills started showing up in Starlog and other pressers.
Yeah, I remember the "pregnant guppy" slur. But geez, when that ship rolled across the screen in 1984, I was in love! What an awesome improvement on the Constitution class. I built it out of LEGO well before any die-cast models were available. Too bad fandom dissed it. If only... If only...