The actual language of the proposed rule change, which would make it an ethics violation to: "harrass or discriminate on the basis of race, sex, religion, ethnicity, disability, age, sexual orientation, gender identity, marital status, or socio-economic status in matters related to the practice of law" is not unreasonable (although I'm not clear on "socio-economic status"). What is troubling is to read the official comments (which are not themselves law, but are "guidance") and the accompanying essay of justification.
Essentially, it is clear that the majority of the committe which voted out the report, and the President of the ABA, would like to use ethics code to police conduct that cannot be policed in other ways. This includes a very broad definition of "related to the practice of law" to situations ranging from networking opportunities through social events sponsored by bar organizations, law schools or other "law related" events, to making work place harassment (including types not covered by state law) an ethics violation.
However much one may like the idea of purging jerks out of the practice of law, that is not the role of the ethics code -- and the intellectual justifications employed are, to be blunt, rather flimsy. When you are citing as precident for an expansive view of "the practice of law" the Clinton/Lewinsky disciplinary action by the AR Bar Association (which was widely regarded in the legal field as a travesty for its violation of precident and clear political motivation), then you are not standing on particularly firm ground (but I will give you points for irony for using Ken Starr to justify your anti-harassment policy).
In law, and in society generally, process really does matter. I grant there is a bunch of fuzziness about law and process. But the notes and report make it clear that this is not fuzzy.