Uplay is necessary. You can get it through steam, but still need Uplay. Can't directly add friends in-game through steam, gotta use Uplay for that.
I played the Open Beta on XB1, game is great fun, but it doesn't use dedicated servers. It is P2P. You get 20% of your games aborted half way through, which denies you points, exp, rewards. People drop in and out of games constantly, which pauses the game and rolls back a few seconds sometimes after the pause.
Ubisoft is going to ruin a wonderful game (again), by being cheap and lazy. They made it so everyone in the match sends info to everyone at the same time, instead of having one person being the host, but behind that "New Innovation" is still Peer 2 Peer networking.
Your NAT type will effect how crappy of an experience you have in the game as well. There is Open (best), Moderate, and Strict.
Mine was Open, and I still had so many disconnects and errors, game aborts. If you can look past all that, and have hope that it will get better with time, then the game is worth it. But its 2017, P2P is not cool. This isn't Quake 1/2 in 1999 where we host our own games. You know Ubisoft has the money for servers, but they already said they don't plan on changing it.