The Internet Archive currently does "host a clone of the CDC site as it existed before Trump took office". Everyone on IA knows, or could find out very easily, that they are viewing of an older version of the site.

The NGO group publishing this website seems to be intentionally misrepresenting the site as the actual CDC. They have altered the information contained on the page to push a specific message that is not backed up by science as understood by the CDC, whose website they are impersonating. The page is designed in such a way to ensure you do NOT know you are not viewing the current CDC.

As this is HN, I'm going to interpret your message in the best possible light. I need to ask a clarifying question:

Does this really seem like a slippery slope to you? Taking down a website designed to impersonate another entity and misrepresent their beliefs will lead to the tyranny taking down the Internet Archive?