Originally Posted by Golgo-13
My thing is, the cure would have been big news around the time that The Wolverine takes placing seeing as how it takes place a mere year after X-Men 3. The fact that nobody so much as mentions it whether it worked on some, or failed across the board, is a missed opportunity in my opinion.
The Post credit is scene is really not part of The Wolverine, and takes place 3 years after X3, so by then, the fate of the cure would have been public knowledge to everyone including Wolverine, hence him not being surprised to see Magneto with his powers back.
Maybe other than Jean's death they just wanted to stray away from X3 seen as though its not well liked unlike the first two X films or First Class.