Yes, its all true. That said, in my professional life I have seen plenty of white men rise in management (along with lots of women also), so its not all men who have been shut out, although things have gotten worse with time. The long term key to staying valuable is to keep learning and growing a genuine and legit base of skill and technical expertise, whereby one can become a consultant. Often enough its the middle management, without technical experience who become too expensive and get laid off early because their value is diminished, whereas by remaining technical you can consult forever.