Ubisoft Studios are different than a company bought by the publisher. Yes.
Wolfenstien New Order and Fallout 4 are both owned by Bethesda. One is made by Bethesda, one is not. There are still different expectations for different developers. Whether or not they are under the same umbrella, or now have a different title than they had before.
Difference is Bethesda is both a publishing company "Bethesda Softworks" and a development team "Bethesda games".
Ubisoft on the other hand is entirely a publishing company. There is no "Ubisoft game studios" because all Studio owned by Ubisoft are Ubisofts studios
Basically when people refer to Bethesda they mean the creators of Skyrim and Fallout. You cant really say the same for Ubisoft because all there studios are basically Ubisoft Studios IE. Ubisoft Bluebyte is no different from Ubisoft Reflections, Ubisoft Montreal or Paris
If you consider Watch dogs an Ubisoft game, then The Division is also an Ubisoft game, since they were developed by Ubisoft Reflections and Massive respectively