MW doesn't even explain the difference between "blond" and "blonde", they just mention that "blonde" is a variant of "blond". With "brunet(te)" they explain it though, not sure why.
Personally I don't care, English is already pretty gender neutral, there are few words like actress, waitress, or sorceress, in most cases it's the same word for both women and men, unlike in Russian where everything is genderized so any attempts to make the language gender neutral are bound to be cumbersome. However I'm aware that many people today are talking about gender neutrality in language. I liked the solution about saying "firefighter" instead of "fire(wo)man" or "police officer" instead of "police(wo)man", no awkward affixes are added and it sounds neat. "Female waiter"? Too long.
As too what do I think when I hear "blonde/blond" I always think of hair colour. Unless someone is talking about the alcoholic drink.