alt Hacker NewsPrivacy extensions are enabled by default on OSX, windows, android, and iOS: https://ipv6.net/guide/mastering-ipv6-a-complete-guide-chapt...
On Linux, I think the defaults are left up to the distros so there is a chance of a privacy footgun there. Hopefully most distros follow the example set by Apple and Microsoft (a sentence I never thought I would write...)
They are now - I'm not sure when they implemented them but I know Windows at least would do some really stupid stuff very early on.