Are already-written entries in the current turn canon?
As far as timing inside the Ghyll world, all entries happen simultaneously, such that they’re all mass-canonized “at once” by the Encyclopedants. But, from the standpoint of the players themselves, once an entry has been written, it should be taken as canon immediately – otherwise, anyone can come along, write an entry that does something drastic, and invalidate all the other entries on that turn (ie., “mass flood wipes out the Folktown Record three weeks ago”, breaking any current turn entries that talked about the latest edition). It’d be suicide to ask all the other players to retroactively rewrite their entries.