A short insight in the office of ubisoft ;D
https://youtu.be/0S0tUjipw2c
They are doing the PTS wich is testing the game by actual players and give feedback about bugs and balancing, it´s being done in phases so they can cover as much as possible and make sure that what they are going to release actually works, and it takes time. Otherwhise, if they release the content quick without testing, everyone is going to be complaining becuase the bugs and the unbalances since they did´t test it apropiately in the first place, and i can guarantee you are not going to like that.. I rather it takes a bit of time and get something good than recieve a buggy unbalanced mess.