Well, Cro Cop deserved his chance to rematch Fedor and try to take that no. 1 spot by winning Grand Prix in 2006. He really had a bad luck that Pride went under at exactly that same time, so he never got his earned shot due to the unforseen cirumstances. It was really a bad luck and lose/lose situation for him, not only that he had to go to cage and unified rules that did not suite him, he also lost any possibility to fight Fedor for no. 1 place. Except money, he had nothing to gain in sporting manner, he was allready better ranked than any UFC fighter, including the champion.
Their fight in 2005 was the hardest fight that prime Fedor faced, and he was on absolutely top of his performance, whie Cro Cop had much space to improve, in terms of condition, focus and tactic, and to learn from the mistakes that he made.
Of course, years have passed and it is not the same time, but I somehow belive that Cro Cop still and allways has that right to another shot vs Fedor.
But once he managed to beat him, Fedor will probably never give Mirko that chance for a revenge, since there is probably no way to force him.