Obviously i can't really comment on the CCCP thing - but i can on what is going on right now:
InRP, ther ehave been meetings and run ins between the gauls and the sairs since the last mod - by the lore, by ingame encounters and some forum stuff -the latter never lifted off as intended due to people disappearing. Now we hurry up to get "up to date" so to say.
The logic, at least to me is simple: The Sairs and the Gallics want to see Bretonia go down - now with the sairs always extending their greedy little fingers towards cambridge they had the option of a, facing the ubermighty armada that is deemed to win anyways from their pov - or to cut a deal.
Now they can start to profit from exchange of military information while losing really nothing. They had no friends before Gallia, so if the plan doesn't work out, they will go back to just that.
If it works out they can enjoy the spoils of war while possibly being on the good side of the mightiest entity in Sirius, simple as that. The people the Corsairs are not hostile to ( Kusari&co, Gaians, certain Rheinlanders) are already on the good side with gallia so there is little to no risk of a political hickup either...
So on the grand scheme of things (and including that we get nudged to fulfill our "lore" ) - it went down quite naturally