My 2012 F150 has what I would basically call a gutter system just for the sunroof. It has (2) drain holes, that you can see with your naked eye, where the water runs to and drains out, if it actually leaks. It runs from top to bottom and drains out right behind each front tire. It is kind of neat. This truck has sat outside its whole life, hot summers and cold winters, no gasket replacing and no creaking, sunroof has been completely trouble free.
Assuming Ford did the same thing or something like it on the Raptor I would not worry about the sunroof leaking at all. Ford already knows the sunroof gasket will leak and already has it covered.
I definitely plan on ordering one for the Raptor. It looks sweet!
Edit: it is possible for the drain to get clogged, especially if you are by pine trees where there are thousands of pine needles falling everyday or something like that. It takes 5 mins to blow the drains out with an air gun and you are good to go.