That doesn't make any sense. It's supported on local phones for both iOS and Android. What iOS does that's special is enable FeliCa for all regions globally. It only affects people from outside Japan traveling there.¹
Since it's not free for them, I assume they determined the amount of people in their key demographic that visit Japan was worth providing a stellar experience. Considering 2.7 million Americans visited last year, it was probably a bet that's paying off.
¹ Or, incidentally, people who live there but purchase phones overseas to avoid an obnoxious camera shutter sound forced on at all times.