Yeah, this works for gear locked behind co-op missions, but not for the Club Competition, Initiate, or Unity Companion App requirements. The Club Competition requirement sucks, and I hope they remove it.
I have only played co-op once on ACU. You have no idea where the other player is in most cases since ACU (Assassin's Creed Unity) has terrible maps and direction finders. Also the player I was playing with killed everything on the map which was interesting but not what I had in mind. As usual with co-op games in order to really have cooperation you need to follow the other player and let them take lead or the whole thing becomes a disaster.
If there was only a game manual, I could figure out what the items on the screen and map mean. The legend does not help much.