https://www.theverge.com/2019/2/7/18213567/twitter-to-stop-sharing-mau-as-users-decline-q4-2018-earnings

Twitter’s monthly user count has fallen for three quarters in a row, so to address the issue, Twitter has decided to stop announcing how many users it keeps losing.

The change, which begins after next quarter, was announced in Twitter’s latest earnings release, where the company disclosed that it had lost another 5 million monthly users during the final few months of 2018. That brings Twitter to 321 million monthly users, down from 326 million the prior quarter. It’s Twitter’s lowest user figure in two years.