Firstly, if the cryptography is compromised the least of my worries is remaining anonymous; you would have alot of other things to worry about.
Secondly, there is something called "stealth address" oh and of-course if that cryptography is broken well then sir you have more more to worry about than remaining anonymous.
Thirdly, see 1 and 2 and oh yeah why not send a note to Satoshi about it whilst you was as it about how dumb his idea was of creating a crypto currency.
That is a very common fallacy. Or maybe you just have nothing to hide?
When the cryptography securing on chain anonymity is broken, everything in there will be revealed. New algorithms will be implemented to secure everything else from future attacks like your coins so they can't be stolen, but what has been put into the chain will be there and can't be made anymore secure.