From that Covert Shores article.
(Astute class) are the only subs outside the U.S. Navy able to launch the Tomahawk land attack cruise missiles, a capability which sets them apart.
This is not correct. The Spanish S-80 class submarines have TTL Tomahawk capability. TTL Tomahawk is out of production and Tomahawk Block 5 has never been produced in TTL format.
The RN is having its stockpile of Block 4 TTL Tomahawks upgraded to Block 5 and the RN and RAN want Raytheon to offer new build Block 5 TTL Tomahawk to maintain capability (RN) and additional capability (RAN for Collins class capability upgrade).
The Marine Nationale use horizontal launch Scalp Naval, which would be another option for the RAN