Think it could have been made an issue because attitude to native Americans is quite topical atm. The Washington Redskins NFL team have been under a lot of pressure to change their name because it could be seen as offensive and even the logo has come in for controversy
It's been happening across American sports apparently, there's quite a lot of teams with native American nicknames like 'Chiefs', 'Indians', 'Blackhawks', 'Braves' etc. who have been gradually dropping their native imagery. I guess this would be in line with those pressures, I wouldn't have thought it offensive but then it isn't really for me to say, if nothing else because I'm not American so it's not really a discussion I need to be involved in