> This raises an interesting paradox to me. How would the people writing the marketing copy for any product that was supposedly Superfish-resilient actually know that it was?

A big difference is that Dell's inclusion of the private key appears to be a (major) screwup by someone with technical responsibility[0], whereas Superfish was downright intentional and involved people all over the company.

In that light, this doesn't really appear to be a paradox - no company should ever market themselves as being immune to mistakes and/or breaches. But it's pretty straightforward to live up to promises that you won't intentionally compromise all security whatsoever just to make a few ad dollars (which is what Lenovo did).

[0] As far as I can tell, there's no evidence that Dell benefits in any way from shipping the private key, so I'm going to invoke Hanlon's razor until we discover otherwise: https://en.wikipedia.org/wiki/Hanlon%27s_razor