Pulev is about 40, Takam is what 39? Ortiz is God knows how old, Stiverne is 39 years old and so is Povetkin. Is it some kind of new rule that a challenger cannot be in his prime to fight for the heavyweight title?
Yes. Except the WBO title. Young contenders are allowed to challenge for that but they have to agree to wear a skirt and fight in youtube.
Ortiz turned pro at 30. It would have been a miracle to see him challenge for a title in his physical prime. Pulev turned pro at 28 and challenged Wlad at 33. Povetkin turned pro at 25 and at 28 turned down a mandatory shot at Wlad. Finally challenged Wlad at 33. Takam is just Takam. He lost to Povetkin and Parker and ended up lucky to get a shot.