Two things of note struck me when reading the article. The first is the following:
Please note the bolded text. While the lead ship, HMAS Collins was laid down about twenty years ago, and the newest vessel HMAS Rankin was laid down about 15 years ago, Collins has only been in commission about 15 years, and Rankin about eight years. While I do not consider the vessels to be 'new' vessels, IMO it is a bit of a stretch to call them "ageing" when the lead ship is approaching the midpoint of her service life. Yes, the subs need maintenance, and yes, the subs will need to start undergoing some sort of MLU. That is normal for a naval vessel with an expected service life of ~30 years. More worrisome IMO is the possibility of some manufacturing or design defect that makes the Collins less effective or available for RAN service. That is the sort of thing which if it does occur, is not the fault of Defence or the RAN, but that does not seem to occur to the writers of the article.
The next item is also below, again note the portion in Bold:
I could be mistaken, and please feel free to correct me if I am, but I had thought that ASC had changed its name from the Australian Submarine Corporation to ASC not long after winning the AWD contract. Part of the reason for the change I had thought was that with ASC building the AWDs, they would be a ship and sub-building concern, and therefore should have 'just' submarine in the corporate name.
The last thing which I found interesting, and while I am not as aware of more subtle areas within Australian politics, it does sound sort of like a political beatup for the defence opposition spokesman to criticise the chiefs about evasiveness regarding sub availability. That strikes me as being the sort of thing which should not be discussed anything other than general terms in any sort of public settings, for national interest/defence reasons.
-Cheers