It looks like the link is fine when clicked by the recipient, but the preview comes up as 404.
Either fb/wa is doing something odd in the request when generating the preview, or the other end is responding badly to something unusual-but-correct that there's are doing. Perhaps due to the initial request's accept headers a redirect is being sent instead of the usual content, and requesting that results in a 404.
Could be malicious as many are suggesting, I certainly wouldn't put it past them, but I suspect cockup is a more likely explanation.
No, I mean I can't reproduce the preview. I think you experienced a fluke. If it was anything else wouldn't that mean that WA wasn't in fact e2ee? Or at least link previews (I know Signal does this client side, I don't know about WA)
