What does the Antonio Rogerio Nogueira signing mean?

WKR posed an answer to this question to Michael David Smith on Twitter,

WatchKalibRun: Also takes away an opponent from Mousasi/Sobral/ Strikeforce.
This is a key point. When the UFC acquires fighters, Dana White isn't only thinking about how those fighters will draw in the UFC. He's also thinking about how he can keep those fighters from drawing in other promotions. A Strikeforce light heavyweight title fight between Gegard Mousasi and Antonio Rogerio Nogueira would be a big one, but that can't happen if Nogueira is in the UFC. With how stacked the UFC light heavyweight division is, it will be very interesting to see what kind of light heavyweight challengers Strikeforce can find for Mousasi.

It appears that the UFC is entering into another period of aggressive signing. Affliction's recent demise increased the available free-agent talent pool and clearly the UFC wasn't willing to let those fighters concentrate into a rival promotion. 

However, while the UFC actively signs more fighters they are also trimming their roster. 

Thales Leites and Jake O'Brien are two fighters with some serious name recognition we could see fighting outside of UFC (would love to see Leites fight Jake Shield or Robbie Lawler). As long as the UFC continues to cut talent there will exist a second-tier fight promotion.

The question is whether this organization(s) will ever challenge the UFC's brand or simply be a D-league or AAA promotion. That will rest solely on the rival promotions ability to build a brand and new talent outside of UFC cast-offs.