Well, if the Catholic church has not budged one bit from any of the positions which are objectionable for the Orthodox, then has it really made the effort necessary to effect a reunion?
What you are saying, that Orthodox Churches disagree among themselves on some issues, sounds like an excuse to do nothing.
It is pretty obvious that if they really wanted to, the Catholic Church could, on its own initiative, introduce certain substantial reforms that would be pleasing to the Orthodox Churches. I can easily think of several such reforms, and many of these are in fact outlined in a harsh letter written by two very hardline Orthodox bishops.
The Catholic Church has had 960 years to straighten things out with the Orthodox. How many more years are required?
Also, (IMHO) I doubt that this meeting at Nicea will be a council. I suspect that it will be just another get-together photo opportunity, complete with handshaking, hugs, kisses, beautiful speeches and expressions of goodwill toward all, and how each Church admires and respects the other, but that nothing in the way of the necessary substantial reform to effect reunion will be accomplished (IMHO). After the “council”, (IMHO) there will still be two separate Churches, not in communion, at least partially because of the unfortunate fact that the Catholic Church has been reluctant for 960 years to make any substantial concessions to the Orthodox and it remains reluctant to do so, at least up until now.
Anyway, being realistic about the situation, that is how it looks to me.