This has all entered the tinfoil hat territory methinks.
Developing something that big and complex could never be done in secret these days or in the 90s.
Indeed.
https://thespacereview.com/article/576/1
Six blind men in a zoo: Aviation Week’s mythical Blackstar
https://www.tmcnet.com/usubmit/2006/03/20/1472209.htm
Blackstar A False Messiah From Groom Lake
Of course there were projects ISINGLASS, Rheinberry and QUARTZ….