No, absolutely not. Legal holds prevent you from destroying evidence, they don't require you to produce new evidence and make it available. The legal theory of the plaintiffs in this case is that using 24-hour-expiring chats is tantamount to destroying evidence every 24 hours. I'm not a lawyer and can't comment on how well this matches with previous precedent in this area, but I get the general vague sense that using "off-the-record" to specifically avoid discovery is often something courts take a very dim view of—even when those chats are replacing in-person conversations and meetings the court would have no way of knowing about before the advent of IM.

EDIT: And the court in this case took a dim view of it as well: https://storage.courtlistener.com/recap/gov.uscourts.cand.37...

> At the heart of this dispute is a simple question: did Google do the right thing with respect to preserving Chat communications in this case? There is no doubt that Google was perfectly free to set up an internal IM service with any retention period of its choosing for employees to use for whatever purposes they liked. The overall propriety of Chat is not in issue here. What matters is how Google responded after the lawsuits were filed, and whether it honored the evidence preservation duties it was abundantly familiar with from countless prior cases. The record establishes that Google fell strikingly short on that score. Several aspects of Google’s conduct are troubling. As Rule 37 indicates, the duty to preserve relevant evidence is an unqualified obligation in all cases. The Court’s Standing Order for Civil Cases expressly spells out the expectation that “as soon as any party reasonably anticipates or knows of litigation, it will take the necessary, affirmative steps to preserve evidence related to the issues presented by the action, including, without limitation, interdiction of any document destruction programs and any ongoing erasures of e-mails, voice mails, and other electronically-recorded material.” Google clearly had different intentions with respect to Chat, but it did not reveal those intentions with candor or directness to the Court or counsel for plaintiffs. Instead, Google falsely assured the Court in a case management statement in October 2020 that it had “taken appropriate steps to preserve all evidence relevant to the issues reasonably evident in this action,” without saying a word about Chats or its decision not to pause the 24-hour default deletion.