True, but those national ideas don't seem to exist anywhere. (According to the wiki, Cossack breakaway states get Cossack ideas, which are not those "Yakutian ideas". Similarly, the wiki doesn't think there are any ideas that add 20% GC.)Cossack revolter tags can end up with truly odd names and flags. It used to be that they broke free with all provinces assigned to the cossack estate, no idea how their land is chosen with the new system.
My only guess is that this nation received randomly-generated ideas as if they're a custom nation.