> When a party reasonably anticipates litigation, they have a duty to preserve documents and electronically stored information (ESI). This duty is codified in the Federal Rules of Civil Procedure (FRCP) 37(e).

I don't like this (it punishes private record keeping) but it's enforced, I believe also by state courts. Big tech companies set impractically short retention policies in general but also put some records on "litigation hold", because they know they can't refuse to comply.