By tradition, shows at the Public (or in the park) list all cast in alphabetical order in the same font.
When those shows transfer to Broadway, that protocol is not followed and stars are listed above the rest of the cast (often in multiple ranks) and sometimes above the title.
At his point there is no way to tell how Miranda will be credited, or whether it will be above the title. (If I had to guess, I would say Miranda and Odom on one line, followed by 2 or 3 tiers.)
So no one can answer your question at this point.
The other problem is that, even if a refund or exchange is available, your options for seeing the show in 2015 will be severely limited.
Word is that the understudy is as good as or better than Miranda. I would not think for a moment about not seeing this masterpiece with or without its creator.