No, but it could've easily passed for a new design, and the Klingon battlecruiser from ENT did retain an identical exterior in the VOY era. The producers' requirement to keep Star Trek mostly the same, as well as some budget constraints here and there, simply resulted in a similar sort of "technological stasis" that is used to explain why the Star Wars galaxy had very similar technology 25,000 years ago. Yes, there is some new technology in Star Trek, but nothing radically new. As a result, Starfleet may view starship exteriors as a set of architectural shapes, some of them repeated by tradition over generations, rather than designs driven strictly by functional requirements. The interior can change, but the exterior doesn't matter as much.