Yes. Correct.
You never licensed or bought the servers, but you licensed a product that requires a server, for whatever reason, to function.
That is my point.
Now, why single player games ~require~ a server has been a point of contention for some time - and rightly so - just for instances like this. This was exactly what opponents of persistent online connections and/or accessible only via a digital storefront feared could happen.
But Ubisoft never did anything they didn't tell you they were going to do - it was transparent the entire way. You bought a license to some software. In the case of DLC, it requires the base game to function, and for multiplayer games it requires an online server to function, and it's only obtainable via their authorized download servers.
They never promised anything else, and people bought it anyway. Hope they enjoyed it while they could.