Though I would guess that having an explicit policy of "don't write down any safety concerns" would do badly in court as well. I suspect any real such policy would have to be unwritten, or a not-very-explicit side effect of something that seemed relatively benign.

Scandals like Boeing's and others that shook trust in public institutions, most of which are required by law to make any such material available to citizens, just convinced them that proactive destruction of evidence is the way to go. This is not punishable by law. And when the requests for data do come in all the have to do is delay the process until the totally legitimate automatic policy kicks in and removes the last shred of evidence.

At this point only whistle blowers diligently collecting all the data before it's destroyed could still help in any way but this comes at great personal risk. And when tools like Signal are involved good luck with that, one would have to be part of every conversation.

I can assure you that any manager or owner on the planet, at some point or another, has a conversation where it is agreed that something will never be written down in any form.