Would a modernised Fletcher still be a Fletcher?

Why is reactivating Fletcher-class ships to fill a modern frigate gap a poor idea?

The few surviving hulls are museum ships, and the changes needed for a modern combatant would amount to a substantially different design.

Fletcher was an effective Second World War destroyer design, but the remaining hulls are museum ships. One survivor's partial sinking is recalled as a further obstacle to reactivation. An up-to-date version would need changes extensive enough to make it a substantially different design. Retaining the historic class name would therefore conceal the scale of the work.