There have been HC snubs who have been white before, former Vikings OC Darrell Bevell never got a job despite getting quite a few interviews over the years. Longtime Saints OC Pete Carmichael coached year after year of great offenses with the Saints and was with Brees with the Chargers through the Saints, but he never got interviews like Bieniemy did. Teams knew Payton was the mastermind of the offense, not Carmichael - just like how Reid overshadows Bieniemy.
I'm shocked Ben Johnson hasn't gotten a HC job two years in a row, though it seems the Commies wanted to hire him so I won't include him on that list.
You can add Canales if you're counting minorities, since he's part Latin American.
I think Pierce is going to get a legitimate chance as he did quite well with the team in his interim stint, he might make it as the "leader of men" hire a la Dan Campbell. I think they also regret not hiring Rick Bisaccia after his interim stint, and they are trying not to make that mistake twice.
I don't have a read on the Patriots situation. Clearly they've been grooming Mayo for some time now, but it's hard to know how much leash he'll get since we don't have a recent history of them churning through HCs. It seems there was some sort of clause that allowed them to hire Mayo without interviewing anyone else - otherwise I wonder if Flores gets an interview. I don't think Kraft cares that he's suing the league.