Well you should ask a lawyer to explain to you the concept of a "document retention policy" long before you do anything that could possibly get you involved in litigation or an investigation.
My point, which everyone seems to be missing, is, if a judged said "You must record all your conversations" I feel like most people on this board would say the judge crossed a line. That being required to record all your conversations, as in carry around a recording device and make sure every conversation you have is recorded, conversation in hallways, conversations in the bathroom, conversations at the gym, conversations at lunch, dinner, in bed (maybe you're dating a co-worker), conversations in meetings. I feel strongly people would object that's not ok, not constitutional, 1984ish, etc...
I get that I should talk to a lawyer. That's not the point. The point is, IMO, recording chat is over the line. email yes, documents yes, chat and video conferencing no. People would find a judge ordering all employees direct face to face conversations being recorded to be unacceptable. To me chat = slightly facilitated face to face conversions. To me it's a slippery slope. If chat is ok today, video conferencing tomorrow, then demand total surveillance next because it will be technically possible (already is). That fact that it's trivial to record chat ignores that it shouldn't be required to be recorded in the first place.
People here are okay with because is popular to hate on Google. You're next.
It is totally common in business for certain broad topics of conversation to need to be retained for legal purposes, especially written communications.
What makes you think "chat" is any different than email?
My (IANAL) understanding is that even if a Judge didn't order it explicitly, writing something like "let's not discuss this in email, meet me in the hallway" can look very bad in retrospect. Similarly, explicitly turning off chat transcripts (or failing to turn them on) when required may not be a good strategy, as this article shows.
From the article:
https://www.law.cornell.edu/rules/frcp/rule_37
"If electronically stored information that should have been preserved in the anticipation or conduct of litigation is lost because a party failed to take reasonable steps to preserve it, and it cannot be restored or replaced through additional discovery, the court [...] (2) only upon finding that the party acted with the intent to deprive another party of the information’s use in the litigation may: (A) presume that the lost information was unfavorable to the party; (B) instruct the jury that it may or must presume the information was unfavorable to the party; or (C) dismiss the action or enter a default judgment."
The law doesn’t operate in some kind of “gotcha” or “this one trick” manner. Judges can see through this crap relatively easily.