I wonder if the previous specificity was due to various union negotiations.

Or simply a culture clash between factory labor and white collar office management

I briefly worked in automotive as a tech worker and we had to completely lock down the slack workspace due to patently unprofessional behavior by many who just seemed to not understand that what you post in corporate chat might as well be painted on a mural for all to see

Imagine what you might hear as banter at a construction site, overheard by HR at a bank

I dont really know how it came to be that way.

Like most bureaucracy it slowly builds up off the 5 monkeys principle.

I do have first hand experience sitting in a meeting as a sysadmin trying to determine if we are a stake holder on the colour of a bolt inside the 5.3L v8 before it came out for the silverado.