It's a big step forward on the business end of things. This isn't something "fight fans" can get excited about, but what it basically means is that the UFC has expanded to the point where Lorenzo and his position is needed full-time, and it also shows they're quite serious in terms of expanding the brand internationally (eg. in Brazil). And, perhaps, it's even more serious considering what Lorenzo is leaving behind (the family business where he's earning a ridiculous amount of money).
So no, on the surface and in the immediate short-term, this doesn't seem like a big deal. In the long term, this is potentially a huge step forward.
It has that feel, but Overeem only fought in Strikeforce a single time after UFC bought it (in Texas, a state that does not drug test.) Overeem spent most of his career in Japan, which does not drug test.