It was someone quite high up in the company who was the first to raise in Slack actually; though it's clear were similarly not highly clued in to this before yesterday, and no substantive replies or info yet (just other colleagues with similar concerns).
I'm guessing this will blow up later this morning when people start waking for the work week.
I work for VzM, but not historically directly on Yahoo products (product teams have been merged/consolidated etc. over the past few years, but there's still strong tendencies toward products people came from).
So I wouldn't be very clued into what's happening with Yahoo Groups internally. And I've heard nothing about this internally. At all.
As it stands, it's 2:30pm in SV, VzM is top of the HN frontpage, and not a single soul has mentioned it yet on internal Slack.
I'm guessing this will blow up later this morning when people start waking for the work week.