Early in the 2nd quarter of 2018, the lead devs of TrueoOS decided to quit supporting TrueOS Desktop and start focusing on the server/base OS market. The official announcement did not happen until the late 2nd quarter. Read this article for more information:
At that time, the 2 devs working on TrueOS Desktop decided to continue working on a user-friendly desktop using the TrueOS base, Project Trident.
For a brief history of Project Trident, read the articles, oldest to newest, located here:
The trueos announcement is located here"