Why early Constellation frigates would still remain in service

If 31 Constellation-class frigates had entered service by 2026, would the earliest ships already be moved into reserve?

Probably not. They would still be viable, designed for service lives comparable to Arleigh Burke destroyers, and needed by a fleet short of escorts.

In the hypothetical 31-ship fleet, the first Constellations would probably remain viable in 2026. Their expected service life is roughly 30 years or more, comparable to that envisaged for the Burkes. They would probably still be needed, making reserve status unlikely.