This is horrifying. Why do you feel the necessity to self-censor? What consequences do you anticipate?
And then add to that how easy it is to record phone conversations with today's phones (I've done it), it's easier on the brain to assume it's being recorded as opposed to wondering if it is.
But yes, I don't care about my dirty jokes being recorded :-) Illegal activity? Sure. But I solve that problem by not doing illegal things.
And yet, we still see comments of people horrified when you said you assume as default that someone (or more likley, something) is listening.
The normalcy bias is too strong.
My primary worry would be things being taken out of context when circumstances change later. Maybe there's lawsuit discovery, or maybe you have a falling out with a coworker who tries to defame you. The last thing you want is a motivated adversary to be given access to a wide trove of things that could be reframed to be used against you.
And it's not just off-color jokes or insensitive comments. At one job, we had a project that involved "fudging" billable numbers for a completely legitimate purpose. I was the one insisting that we don't use that term in writing at all to avoid any potential future misunderstandings. Call it an "adjustment" or "algorithmic modification" or something, but not "fudging" or "fabricating." Same kind of reasoning.
And I make a point of seeing the people I care about face to face.