[evah]

Tilde.club nearly meets your definition.[1] It's at least 1 decade and 15 days old, but it appears it's open to join for anyone.[2]

[1] https://tilde.club/ [2] https://medium.com/message/tilde-club-i-had-a-couple-drinks-...

[hyggetrold]

The first link you put gives me a security warning so I didn't click through. But the medium article would suggest that this is the one!