While I get where you guys are coming from, I don't really think it's a good idea to essentially remove the Idle Chat feature from the game. It's one of those things that makes the game more realistic, you know? Yes, it may disrupt a sim's action queue, but if you don't want them trying to converse with other sims, I suggest turning off your Autonomy settings. But if you don't want that, maybe only disable Autonomy for selected sim. What I'd suggest to somehow solve this problem, even I experience and sometimes get annoyed by, is to have it in the settings so we can toggle Idle Chat on or off, like opting sims out of Fame i Get Famous, or disabling the Civic Planner and/or Eco Footprint i Eco Lifestyle.
There are mods that goes in-depth with Autonomy scanning like MC Command Center, but it's safe to assume that not everyone wants a mod in their game. I used to be. There is also a mod that makes these unnecessary idle chatting by actually choosing random social interactions between sims. Though personally, I don't like that mod because I don't want my sims to randomly Discuss Local Fishing Spots. Best thing we could do is to immediately cancel our sims' queued Idle Chat before they could start the action. But another problem lies with the action queue itself: sometimes, it doesn't do actions in order, and sometimes it doesn't cancel actions immediately.