Should MCU Iron Man be recast as minority??

I found this (from Will Smith) pretty funny:

Before he played a villain in the DCU's "Suicide Squad," he was in contention for DC's biggest hero: Superman. So what derailed his plans to put on the cape? "Wild, Wild West." Kind of. "The script came, and I was like, ‘There is no way I’m playing Superman!’ Because I had already done Jim West [of 'Wild Wild West'], and you can’t be messing up white people’s heroes in Hollywood!” Smith told MTV in 2008. Laughing, Smith added: “You mess up white people’s heroes in Hollywood, you’ll never work in this town again!”

https://www.moviefone.com/photos/iconic-roles-will-smith-turned-down-the-matrix/

Yes and no.

Yes in the case where it fits to have a qualified actor or an actor who gave a better audition and/or screen testing to have the part. Idris Elba has been a great Heimdall, who cares if he's black.

No in the case of situations where the character is tied to his or her specific race, ethnicity, or gender. Whether its Stan Lee, Steve Ditko, Bill Finger & Bob Kane, or Ian Fleming, it'd be dishonoring the original intent of a character's creator. For instance, the talk of recasting James Bond as Jane Bond. Writers in film and video games have already done media like Salt and Columbiana instead of recasting James Bond. Tomb Raider worked just fine with Lara Croft instead of recasting Henry "Indiana" Jones as Henrietta Jones.

I do tend to lean to the side of 'may the best actor get the part'.

http://www.thewrap.com/night-living-dead-casting-cult-classic-20545/

On George Romero casting Duane Jones as Ben in Night of the Living Dead.