Hi,
Good motivation, personally I think that kind of replacement is a good thing to do with blacklist/whitelist (as is happening with flag names in the Node Exporter). But I don't know how people feel about blackbox / whitebox yet, as it doesn't carry the same negative/positive association with colors. It would mean more invasive changes, like renaming the entire repository and related documentation web pages, and potential Google findability confusion (old blog posts etc. mentioning the old name).
I haven't heard blackbox/whitebox crop up in the same way as e.g. blacklist/whitelist yet, but would be interested to affected Black people's opinion on whether this seems troublesome as well. If this turns out to be offensive to affected people, that'd be a good argument for renaming it IMO.
Julius