Considering that Cinco de Mayo is a hyped-up American holiday, and is not taken too seriously by Mexicans (their independence day is on September 16, not on May 5th), it seems outrage over costumes and parties is misguided.
But, a women’s lacrosse team in western Massachusetts held a Cinco de Mayo-themed party and an Instagram post garnered criticism. A player on the Western New England women’s lacrosse team joked about President Trump’s border wall, which may have been the focus of social media criticism.