In the first place, the game needs to be active for them to know the errors. The usual and common preparations are already applied but some errors and bugs will just be known once the game turns into a live one. The trial and error period will be on Alpha, Beta, and so on.

As far as Ubisoft's name is concerned, they are in the gaming industry for a long and already encountered lots of game bugs along the way to their variety of games so I'm sure future problems will be addressed properly.