That's another thing. The Enterprise was going to be taken out of service in III, but I always wondered if another Enterprise was on the drawing board. Perhaps the E-B was to originally be its successor, but the E-A was quickly rushed into service? It's fun to theorize about.
Could be. But she was in service from 2287 - 2293. I doubt it would take them 5 yrs to build the B. Not to mention, the Excelsior class completed her trials and a 3yr mission under Sulu's command.
She should have taken a mortal beating by Chang. Sufficient damage to warrant such an early decommissioning.