As I said, it also matters how much you personally care about Heimdall. He was a nothing character in the comics so no big woop to me. MCU changed the Asgardians to multiracial characters who were apparently co-opted by Earth's Scandinavian population. I was personally more annoyed that they didn't make an effort to give Thor his comic book personality and manner of speech - they could have even explained it by having Thor appear on Earth most recently in Shakespeare's time and that's wheren he learned English.
I should point out something though about Heimdall's skin color. You only have to look at the MASSIVELY positive reaction by African-Americans to the Black Panther movie that representation absolutely matters. Nearly all the most popular heroes were created before 1970 by white men to represent themselves. The suggestion that the movies should create their own minority heroes can only go so far. There are constant criticisms online against the so-called agenda of representation. However, it seems to me that when they are pointing and complaining "Agenda!" that there are 4 fingers pointing back at them saying, "Maybe you have your own agenda!" - whether it's a conscious one or otherwise....