Of course, Bethesda was inspired by both mods for oblivion and morrowind and other games, and also by other games, they play games, look at their features and think "this is cool, should we add something like this to skyrim?" Skyrim's features are not oblivion's mods, they are merely inspired by them.
They aren't trying to make a better oblivion, they're trying to make as good Skyrim as they possibly can right now.
Todd Howard has stated this tons of times.