Since it's slight changes due to different markets and audiences, Nintendo just passes it off as some simple "localization" tweaks. Although this does cut down on the content for other regions while Japan gets everything, it's not as bad as it seems. Also, due to the nature of this thread discussing about cut content and such, please avert your eyes if you want to avoid any
spoilers~
I've heard rumors circling around about the N.A. release of Fates, mainly concerning the controversial topic of spiking Soleil's drink, and the removal of the face-rubbing/FE Amie feature. If both of these rumors are proven to be true, the former is simply a change in supports. NoA isn't removing any supports; they're just replacing some very,
very ill-written material with hopefully better supports.
With the latter, unless you're a creepy pervert who likes to pet people's faces and listen to them say... some rather
interesting lines, I don't think this will be missed very much. Granted, it's unfair for Nintendo to remove an entire feature of the game just based off of different regions, but I suppose it isn't enough to warrant a court case or anything of that degree.
Also, I believe most of these tweaks were put in place to lower the game's rating. In Japan, iirc, the games were rated for 15yrs+, while Fire Emblem games here are traditionally Teen (13yrs+). To reduce the game's rating, they probably took some of the more mature content out.