The Clones have said that their second-line fleets of Cosmos CA and (possibly also) Kalahati Tuul S which comprise around 50 ships and perform basic patrolling will be replaced in the early 2120s by the Cosmos CM. These new ships will be designed for operational flexibility and extended range (which is why a variant of the Shark was not suitable) as well as being "capable but affordable".
The remaining Cosmos CA will be replaced first as they reach their end of fatigue lives in the early 2120s and the KTS could follow on afterwards.