Yes yes by refit I mean the new design. Not meaning that it was "refitted" from something old, but not sure what else to call them. Constitution version II perhaps? but yeah I agree that the Endeavor and the rest were probably part of a line of newly constructed ships, which is why I see no reason why the Enterprise A couldn't have been from that line
-A being a renamed older Constitution-class ship would probably be the easiest
way to explain why Starfleet decided to decommission the ship rather than repair her, but there are other ways to explain that as well (one theory I came across years ago was that while the Enterprise
-A was retired, the actual ship itself was repaired, renamed, and relaunched as something else--a variation of the Yorktown
theory, in a way).