That’s just showing the same thing I pointed out before.
Are they disciplined because they did something to deserve discipline? (Meaning black kids act up more than whites.) Or are they disciplined because they are back?
Your links don’t address the reason for disproportionality. It just points it out.
WW raised the likelihood (and I concurred) of socioeconomic factors having more influence than mere race. (Suggesting that those socioeconomic factors are more concentrated in minority demographics.)
As an example, in a classroom of all one race (regardless of race), kids requiring discipline would be more concentrated among those from single-parent households and/or kids from lower-income households.
If those factors are more concentrated in a given racial demographic, then the suggestion is that need for discipline would be more concentrated in that demographic as well.