Navy has issued the KPP for the MQ-25 Stingray.... all 2 of them.
https://news.usni.org/2017/07/20/nav...all#more-26935
Alert 5 has been asking if LM should bid the S-3s in storage for the role.
Alert 5 » Poll: Should an unmanned S-3 compete for the MQ-25A program? - Military Aviation News
I am unsure. It might seem simple to take an existing airframe and convert it to a carrier based UAV vs converting or building a dedicated platform. But with the modifications to all the instrumentation and controls to handle the job autonomously to modern standards (look at the problems in getting the MQ-4 up to German/EU standards) and the landing and then deck handling requirements it might be more costly.
e.g. the UCAV had a plug in socket where the deck handler could plug in an walk it round the deck behind him. Not really a problem with the small concealed engine intakes. Not try adding one for someone to do the same thing safely with the S-3 with both engines running.