> Were these actual concerns that were raised by the actual legal council of the company, or were they issues invented by engineers who are not lawyers but suffer from engineers disease and think that knowing to code means they are experts in everything else? 'Cause I know plenty of those!

the general counsel and thus the entire legal org required for any company approved comms system a way to automatically by default destroy chat logs after 7 days (and to turn that off for folks who were on legal holds). slack in 2016 did not have that capability.