It's commonly acknowledged that content follows the chronology in which it was released - that is to say everything released in 2.0 happened before anything in 2.1, everything released in 2.1 happened before 2.2, etc. While this can get a bit screwy, it's important to remember because it prevents certain paradoxes from occurring.

The easiest way to understand it is "Zombie Nanamo," as I call it. While we now know she's not dead, the events of 2.55 painted her as such. Yet it was still possible to do the CUL 50 quest, during which you prepare a feast for Nanamo, leading to a temporal paradox. The only way to make sense of it is to assume Nanamo is (was) a zombie, or to place all events from 2.0 as happening before the pivotal events of 2.55. If that's true, then patch events almost certainly all happen in chronological order, as described above.