Here the question is not how to do a TKN, but how to prevent the archival in SWH. There is no current approach that prevents that.
We are discussing technical formats that can answer this use case, but this is not yet on the roadmap.
@bchauvet can you confirm?
I do agree that in the FAQ we can add the question "How to do a Take Down Notice" and refer to the existing legal page.
Technically it is possible to prevent from archiving some content (blocking mechanism), but this is only used in the context of a TDN (when we remove a content whose origin is still publicly available). Indeed, the discussion about how and whether to enable such a feature to the end users is actually under discussion, and not on the roadmap yet.