The racism isn't from noting the race, it's from attempting to proclaim that the competitors are not Americans due to their race eg being Asian. As an example, that claim was made up and down the threads on Reddit about last year's US Olympiad win.
The U.S. does have a long history of importing foreigners to win competitions, so it's not really an unreasonable suspicion. E.g. a large percentage of athletes at Harvard are from Canada or eastern Europe, since their grades and SATs don't get included in the U.S. News & World Report rankings.
Harvard does have good hockey teams
Rowing, too. It's substantially harder to win races when your school isn't allowed to import eastern Europeans for that purpose.