Scratch the above as a possibility for the next update. TGC's community manager has confirmed they won't be doing something this ambitious with the first update.
This didn't get addressed in the official reply to my question in the HBS forum, but it was said that the graphics improvements would be "incremental". A jump to 4x msaa might be too much of a leap for one update... maybe 2x msaa then?
The XB1 version really needs some help with its graphics though. Try playing Ross Hollow GC, which is one of the official courses that you can play offline. Even offline, it's a chop-fest!?