I was told to comment on this subject in the gameplay forums so that is why I am making this particular thread.
As the quest stands right now to upgrade a 99 mythic you have to have completed the mythic questline to view the cs so that Oboro will give you the quest.
I have a 99 burtgang that I obtained through Mog Bonanaza.
Now I understand the view point that I didn't "make" my mythic the normal way.
but that's not really the point of why I feel like if this isn't a bug (which no one has came out and said that it was yet) that this really unfair.
If I had known that in the future I would have to make another mythic to get cutscenes I would have taken gil when I won Bonanaza and farmed gil to buy the alex to make my burtgang.