Or they have no control over the release date and feared all this hype over an imminent release would hurt them if it takes longer than expected.
As I see it, the project seems to be almost ready, but still missing things they think it’s important to have on the v1.0 of it. And those things seem to be out of their control.
They probably had a meeting and decided it would be better not to share too much as people were getting the wrong signs (hyping up an imminent release, like I said above). Good or bad decision?! We will see.