Not a lawyer, but I don't think it's unusual to have a retention policy that says when documents should be deleted. This is apparently legal as long as it's a blanket policy. (For example, by default all email gets deleted after a year, unless someone takes action to save it.) Of course anything under legal hold has to be kept.
It's also not unusual to make sure employees know about attorney-client privilege and how to use it properly, or that you should avoid discussing legal matters in a discoverable medium under the assumption it may be used against the company in a lawsuit. This is basic employee training stuff.
So, yeah, no. Sometimes maintaining a paper trail is the thing to do but this isn't the only thing companies do.