Are king crabs really poised to kill all endemic invertebrate sea life in Antarctica?

King crabs from the deep invading shallow Antarctic waters
and eating gentle invertebrates! [start screaming now!]

I am a bit skeptical.  I would suspect crabs occasionally move in and out of areas.  Cycles in the Antarctic are not necessarily seasonal, but I find it hard to believe there have not been periods of warming over 30 million years.  The article claims that this unique underwater ecosystem in Antarctica has been protected and isolated for 30 million years, but this comment at the article makes a good point:

Comment by Carlyle on another article: "So although the West antarctic melted entirely 3 million years ago, the original authors claim the crabs MAY have been excluded for fourteen My, just for luck SIAM doubled it & then rounded up a further 2 My & when I challenged them they deleted my post. I hope you can begin to see that this is not aberant behaviour. It is typical. You can look up the Ice record for Antarctica yourself if you doubt me. There could even have been later melts & almost certainly numerous times that match the present." I did not see the original post, but why would SA delete this?

I am guessing these "monsters" are delicious with drawn butter!  

Maybe we can convince the Japanese to leave the whales alone and focus on this ocean menace! 
Update:
Are gentle sea pigs in danger?
California cold snap threatens citrus crop...