According to Wikipedia, their last acquisition was Pitchfork in 2015. That's almost 10 years ago. Prior to that, the last popular property appears to be Ars in 2008 and reddit, in 2006. They don't actually seem to be buying many properties...
Perhaps that is closer than we think
Granted, Si Newhouse bought it in 1985 - the only time the magazine's ownership changed! - and so maybe it enjoys a sort of grandfathered status at Conde Nast even with Newhouse dead?
I mean, I say that, but they recently ruined the previously-excellent iPad app, which has resulted in me going back to paper issues, but if that's the extent of the tomfoolery I'll take it.
Fake comments, more pliable moderators, dead subreddits are everywhere now.