Let me guess ... B757 pilots?
where is all this leading
It seems that Boeing is returning to the technical solution that existed 40 or 50 years ago on the B707 and on the DC8. The new Dreamliner no longer uses Bleed Air from the engines for Pressurization and Air Conditioning.
kept so deliberately hush hush
Doubt that the issue will ever come to be officially admitted.
Admitting that the problem exists just cannot be allowed to happen. Liability risks would be beyond belief.