The reason is, there is no release of LibreCAD V3 yet. I wonder too, where this information came from.
The GUI is still work in progress so the current state is mentioned to be alpha. And as there are no concrete plans for a public release, there is no packaging or binary distribution yet.
Github is updated with commits from developers in this state and as LibreCAD is pure community driven, there are times with more or less activity.
investing less than half an hour into Search function can save hours or days of waiting for a solution