A friend at Meta -- long before the age of LLMs -- got paged at 3am for a site issue. When he found the PR that caused the bug, the testing section for the change simply said:

YOLO!

This was well into the "Move fast with stable infra" era of Meta, but clearly that still encouraged "Move fast and break things" for everything beyond infra.

PMs landing Prod diffs sounds like even more moving fast shall ensue.