Some (pretty rare) good news on ocean acidification?

Researchers discover oysters can adapt to climate change - ABC Rural (Australian Broadcasting Corporation)

From the article:

Sydney rock oysters can adapt to ocean acidification, a key effect of
increased carbon levels, within two generations, researchers have found.

Research on Sydney rock oysters and ocean acidification has been going on for years, I believe, although I bet that most of the public is not aware of it.

Two things make me cautious, though, about this apparent good news re adaptation:

1.   in the US, ocean pH has already been clearly implicated in widespread oyster die off in certain coastal parts where upwhelming deep water already causes big pH changes.  So, the thing is, while oysters may cope with gradual average changes in pH, I wonder whether even in Australia they might be made more susceptible to temporary drops in pH when  the average has gone down.

2.  I think the evidence from the last huge ocean pH change was always that clams dominated the ocean floor, so I am not surprised that bivalves might be able to adapt.  However, there is also little doubt that the last event involved acidification at a much slower rate than what we are doing, and still the oceans ended up having a huge extinction of species.   The success of oysters may well be not that much to celebrate, even if they are tasty.