The face of this franchise is a changing and there is little set in concrete moving forward. This is why it was wise to sign Gagner short term. The Oilers can ill afford another Horcoff or Khabibulin type signing as they unfortunately already have two of them (three is you include Souray). The Oilers have to be much more fiscally responsible as they are finally bringing in guys that should realistically command that kind of money in the relatively near future.
If Gagner wants to be paid like a first line center then he had damn well better play and produce like one. He will be surrounded by some potentially elite talent and 40-50 points just won't cut it anymore if he wants another significant hike in pay. The Oilers need to pay players relative to what they are worth not relative to the position that they are forced into because they are without better options.
A lot can happen in two years, the Oilers could suddenly end up with a Couturier or Nugent-Hopkins which would bump Gagner into the #2 slot at best long term. Gilbert Brule could continue trending upwards and outperform Gagner, Hall could move down the middle, the Oilers could use Gagner as trade bait, any number of things could happen. The Oilers needed to remain flexible because quite frankly everything is up in limbo right now.
Tambellini has done a very good job this summer, he obviously has a vision and he is thinking at least three years in advance. With Daryl Katz' blessing, this could be a very successful rebuild. For a player like Gagner that was handed so much at a young age it's important for him to get some fire in his belly to take his game to the next level. The fact that the Oilers only wanted to sign him for two years should send him notice that he has been given enough and whatever else he gets from here on out he'll have to earn.