Interesting articles ORAC but I can't see tyhem developoing a new sub in 9 years.... and
"Unlike the VIRGINIA Class Submarine, which was designed for multimission dominance in the littoral, SSN(X) will be designed for greater transit speed under increased stealth conditions in all ocean environments, and carry a larger inventory of weapons and diverse payloads. It will also be designed to retain multi-mission capability and sustained combat presence in denied waters, with a renewed priority in the anti- submarine warfare (ASW) mission against sophisticated threats in greater numbers. SSN(X) will be required to defend against threat UUVs [unmanned underwater vehicles], and coordinate with a larger contingent of off-hull vehicles, sensors, and friendly forces. (Budget-justification book for FY2022 Research, Development, Test, and Evaluation, Navy account, Vol. 3 [Budget Activity 5], p. 1301.) A Navy official stated in July 2021 that the Navy wants the SSN(X) to incorporate the speed and payload the Navy’s fast and heavily armed Seawolf (SSN-21) class SSN design, the acoustics (i.e., quietness) and sensors of the Virginia- class design, and the operational availability and service life of the Columbia-class design. (Justin Katz, “SSN(X) Will Be ‘Ultimate Apex Predator,’” Breaking Defense, July 21, 2021.) "
Doesn't sound cheap - in fact it sound very expensive. The Seawolf programme was canned because of the cost - and yet they want a Seawolf type sub again. I suspect its far more likely they'll get a lot more "Virginias" - if there a shortage stopping an ongoing programme and starting a new one isn't a great idea