https://mobile.twitter.com/RikhGamin...53609549070336
I guess they said they couldn't keep up with all the people leaving the game and finding replacements for them.
I hope the link works as I am posting this from my phone. If it doesn't work, you can just look up Rikh's Twitter page, who is the top mage in their guild and also a popular twitch streamer.
Edit: Thank you @Swordfish Trombone for finding the longer explanation posted by Treckie: http://www.twitlonger.com/show/n_1spfqhm