I think the new incentive is dumb. It seems like the kind of rule that people who don't really understand the problem would come up with because they honestly think it is a solution. I doubt that modest gains in the draft will be enough to push many candidates of color past another candidate, and it doesn't address the root of the problem.
A poster earlier mentioned that the problem is the league doesn't do a good job developing coaches in the pipeline, so that the market remains bare. A majority of head coaching hires appear to be former offensive coordinators and QB coaches. Since the men who hold those positions were typically QBs at some point, if not the NFL, in college, the root of the problem, to me, comes back to both a bias in a lack of black quarterbacks, and a bias in hiring offensive-minded individuals for head coaching positions, which is a trend in the league. 19 of the 32 coaches in the NFL come from offensive backgrounds, and a number of the defensive-background coaches have been around for a really long time (BB, Tomlin, Carroll, Rivera). The trendy highers tend to be the offensive guys. That doesn't mean that offensive-minded guys are the best hires, a lot of the aforementioned successful coaches in the league were defense guys, but the rush to get the next offensive genius is going to hamper the chances of more black candidates emerging.
We know that black athletes who are good QBs in high school are frequently encouraged to switch positions in college (this also happens in the NFL, but probably less frequently). A lot of times that is a good thing for the player, they end up going further playing another position than QB, but at the same time that means less black QBs are entering college systems, which could eventually spark a promising player's potential to begin coaching as a QB/WRs coach, on the path to becoming an offensive playcaller. Most of the NFL coaches were not great professional players, but most of them did play in college and got their start coaching as an assistant at the collegiate level. Over the years the entire football system has gotten better at promoting black quarterbacks, so hopefully the pool of black QB coaches and offensive coordinators will grow as an effect of that.
Maybe I'm not cynical enough, but I don't think most NFL organizations are passing up amazing head coaching options because they are black.There could be situations were two candidates are basically equals, but a biased owner or GM may chose a white coach over a coach of color, but I think the NFL is so competitive that teams are not going to pass over someone that they think would be a great coach, but doesn't take them because they are black. It of course, is possible that the REASON they don't see them as a great coach is because they are black. I'd say that out of the current former NFL coaches who are men of color (Marvin Lewis, Hugh Jackson, Herm Edwards, Lovie Smith, Mike Singletary, Vance Joseph) I don't think that they would inspire many fanbases if they were brought in.
The problem is that the talent pool is small. I think that more black quarterbacks at both the pro and collegiate level will lead to more black assistants and coordinators, which will create more attractive candidates for head coaching positions.