At google's scale, it's virtually impossible to NOT have mountains of "incriminating" conversations.
Also, it seems arbitrary that OTR chat should be recorded but hallway conversations and phonecalls are ok to delete...
If you regularly create records of conversations and phone calls, evidence preservation rules apply to those records as well; you cannot delete them, either.
The fact that no records are usually made in the first place and that the only evidence of the content of such conversations is witness testimony not records means that evidence preservations laws don’t apply (but if you tamper with the witnesses, that is a fairly serious offense.)
Do you believe lawyers and judges are unfamiliar with this issue?
Like their entire lives are spent reviewing documents, letters and email. They invented the concept of Disclosure before computers existed, so that Defence can rebut or put proper context to any argument that will be made by prosecution.
Then, the entire point for some lawsuits existing is to set the stage for that information to come out for no good legal reason.
You can think of it as legal hacking.
I regret writing that last sentence.
They are absolutely familiar with this issue and if you've ever been in any legal case, they'll gleefully exploit every small word to make you look like the biggest criminal rapist in the world and maximize the time you spent in jail.
Go read why exactly do we support Signal and other E2E encrypted messengers. Establishing precedent that every word you say while WFH can be used against you for decades is problematic no matter how much you hate Google.