but old iron side is still on the US Naval registry as a Naval Vessel and kept war ready, though I highly doubt it would ever be called to war. Also cost wouldnt be a factor in this time period kirk states very clearly they no longer use money, so does picard, i would assume federation credits then are used with dealings with non federation speicies but given that the federation has its own dilitium processing facilities and most likly mining facilities upkeep to run the vessles wouldnt be that large. Also we know Starfleet brought the constellation online as early as 2285 according to the USS Hattaway, but the vessel is nearly as large. Another thing by the 2360's starfleet operates lighter ships much larger than a connie, in a lighter duty capacity. So size and cost wouldn't factor in to be honest. The Connie wouldn't be affected by the Kitomer accords it wasnt a war ship it was classified as an Exploratory cruiser, but this might be why the soyuz class was decomissioned. Also by the time the A is retired it is 7 years old, and we only know canonicly of one Exclescior vessel online yet, so why retire the fleet. Also given the tensions with the romulans that lead up to the tomed incident retiring a front line ship also makes less sense given the lack of Excelscior class hulls at the time. Even by the 2360's the Excelsciors we see appear to be built from sumation in the 2300's given the 5 digit registry and not the tradition 4 digit of the 2200's, as can be refranced with by 2285 we where only up to the 2000's in registry numbers, so a sh*t to 5 digits had to occur at some point in the 2300's. Also if all ships where relcassified with the new NCC numbers that still doesnt tell us when they where brought online but from the proof we have only the Excelscior was active in 2293. With the EnterpriseB in 2294 making the 2nd offically commissioned ship. To abdon the connie at this time would not make sense in the slightest. That would leave the Federation 2 Excelscior class vessels in 2294 and alot of mirinida's oberths and constellations