The following is from a well informed source on another forum - I didn’t expect the third boat to be a new build.
”Australian SSN Update:
Of the 3 submarines to be transferred from the US from 2032.
1st and 2nd will have at least 20 years remaining service life after transfer and will be transferred from the USN fleet.
Vessels to be transferred is under negotiation.
(As the Virginias have a 33 year service life, that means the transferred subs will have to have entered service from 2019 or later. So will be a Virginia III or IV.)
3rd Sub will not be transferred from USN but will be a new build straight from the shipyard. As the USN has transitioned to Block V production, Australia would have to specifically request an earlier Block if they did not want to take a Block V.
Source: Vice Admiral Mead
Senate Estimates 31/05/2023
Transcript not yet available on Senate Website.”