F-35As are unlikely to be intended as Dreadnought's successor

Could the F-35A purchase be intended as a successor to the Dreadnought submarine deterrent?

That interpretation is rejected: the aircraft are unlikely to outlast the SSBNs under construction, and removing the submarine deterrent would be a much larger strategic change.

The suggestion that F-35As are intended to replace the submarine deterrent is rejected. The aircraft are not expected to remain in service as long as the ballistic-missile submarines being built. The submarine deterrent is also regarded as a foundation of British security and a major component of national status, making its removal a much larger decision than adding a small aircraft fleet.