Last I checked, Khaled was trying to minimize the number of options, not add more. Adding a switch for every minor detail about program function is fun for users, but not for the maintainer. I personally don't think this is a big enough deal to warrant a setting, let alone command switches.
If you're doing this in a script, you can just not use /disconnect, anyway. No need to add a switch to make /disconnect behave like /quit when you can just /quit.
By the way, there is already an "exit confirmation" dialog that pops up on exiting (by default). Your proposal would add yet another dialog, making for a pretty ugly UX. There would now be two boxes to click if they wanted to exit and bailout. They could change options, but this is what new users will be seeing.
