https://wikitech.wikimedia.org/wiki/HTTPS/Browser_Recommendations is linked from https://en.wikipedia.org/sec-warning It included this text:
This means that if you use an old web browser, you can still read pages on Wikipedia, but your browsing activity cannot always be encrypted in a secure way.
I take it this referred to an earlier set of updates, but it's no longer accurate, so I've removed it. The remaining paragraphs should probably be reworked too, though, since the future they describe is now reality. :-)