Okay, not the same entire coupe seat, but the identical bolstering of the coupe seats.
The coupe seats are less bolstered and therefore roomier than the sedan seats.
Coupes are arguably more trackable than sedans and if MB reduced the bolstering on the coupe seats, maybe they will reduce the bolstering on the sedan seats this year.

I love how supportive the sedan seats are but the bolsters push my shoulders forward -- there just isn't enough width across the upper back of the seats.

Or maybe this is just wishful thinking on my part as I like the coupe seats better but I ordered the sedan?

 

You are wishful thinkinig. Sedan C63 seats are one of the best and is as or even more supportive. Plus the one piece design is safer for tracking. The coupe does look better because it's new.

 

I doubt it... the coupe seats are designed the way they are, in part, because they fold forward to allow access to the rear. There is no reason to put them in the sedan where a fold forward action is not needed.

Having sat in both, I find them fairly comparable in comfort and support so both are great IMO. The only advantage of the coupe seat is the headrest which is neat looking.