As I have been curious about this for years, I am glad to see the below. The bold is mine and was not in the original article.
MLB announced on Friday that 100 percent of all royalties earned through the sales of on-field apparel on Memorial Day will be given to the Tragedy Assistance Program for Survivors and the Folds of Honor Foundation, for a minimum $500,000 collective donation. “For the first time in 2018, we are donating our royalties to two specific charities that really follow the true meaning of Memorial Day,” said Melanie LeGrande, MLB’s vice president of social responsibility.