The Zen and astral diamond exchange (ZAX for short) has been in a weird place for a long time. Cryptic put a hard cap of 500 on how many astral diamonds you could buy for one Zen, but this hasn't matched up with supply and demand in a long time. The end result was that any Zen that was being sold was snatched up pretty much instantly, while there was always a backlog of millions of astral diamonds waiting for buyers (because they could only be sold at a rate that most buyers would have considered unfavourable).
The leadership changes announced on the forums aren't even live yet and already panic buying has set in. People ask themselves where all their astral diamonds are supposed to come from in the future. Within two days the entire backlog has more or less disappeared as people are trying to buy up AD while they are still available.