4-while fixing the bug with bitcoind they discovered a flaw in the protocol which would crash bitcoin and its derivates instantly to Zero.
4 Would be pretty damn scary but I doubt it is the case. Why would ukyo and cryptocyprus team be working on fixing the bitcoind protocol instead of the lead devs?
They would of course, but in the meantime for bitcoin's survival they have to keep silence and calm the mob which is organizing a witch hunt.
If we could just know what happened I am sure it would put the community at rest
Please don't understand me wrong. I definately have no reason to believe that 4 is the case. I try to help to imagine that there might be problems which are better not comunicated until they are sorted out.