No surprise, the new CEO fired the team responsible for detecting and taking down bot accounts. Previously these teams were taking down 500,000 bot accounts every day, which suggests that Twitter might be accumulating 3.5M bot accounts every week.
That said, I'm not sure I agree with the assertion that because Twitter fired that team their bot-busting capability instantly dropped from 500k/day to zero/day. The code they wrote and the work they did still exists.