That argument was made about the Lion King during its initial release, but it didn't gain much momentum. It's usually just people with too much time on their hands.
The hyenas were supposed to poke fun at Hispanics and black street gangs. I don't really see how the film made fun of their race, but having Cheech and Whoopi provide voices of bad guys must have upset somebody.
Scar was supposed to be a gay stereotype. Why in America do people find the British accent effeminate? Now that's just plain ignorance and cultural stereotyping if you ask me.
In the musical number "Be Prepared", Scar and his army march very much like Hitler's army. This was intentional. It was to show that Scar was a dangerous leader and a very bad guy.
Some people were offended about white actors portraying lead characters set in Africa. All this discussion borders on the ridiculous. Anyone who makes such an argument should be made to watch crummy off brand cartoons!