Rising Event

[Ceridwenae]

I really don’t understand why this would be a thing in only the French client, is what I’m saying. Because the English client didn’t give that. So, for one, why put a message like that in one language but not another, and two, why delay the main part of an event/make it randomly spawn?

This makes zero sense to me.

It does say that in the English language version as well, though (edit: although, not really, it's much more open to interpretation). Check with the Rising attendant, any city: The Calamity Retold > Joining the fray. (edit: It's just not as explicit, just saying it occurs throughout. So, you're right there for sure.)
As for why random spawning? I have no idea. Perhaps they think that at some point no one will do it if it's open all the time during the event?