It doesn't matter if the decision was intentional or coincidence, the fact remains the most popular TV cartoon in history has trained our expectations.
race-neutral smiley faces and LEGO minifigs predate The Simpsons—you're just taking your personal experience and projecting it onto everyone else.
Sure, but Lego didn't have brown and black for POC. The training of expectations isn't exclusive, and more people consumed The Simpsons than Legos.