This is a Paradox Interactive published game, not a game made by related Paradox Development Studio which makes HOI, Europa Universalis, etc.

There's no direct relation.

While Colossal Order is not a Paradox studio (besides Paradox Development Studio, they also have Paradox North, Paradox Arctic and Paradox South), it has very close ties to Paradox Interactive. Colossal Order was present at Paradox's Fan Gathering at Gamescon in Cologne this August for instance.