Agreed. The honking has two sources.
1. When you leave the vehicle while it is running...with the fob in hand (not in the car). It does not honk on my 2016 XLT XL or 2017 Suburban. It did honk on my 2015 XLT XL and happened on my 2014 Cadillac ATS. I don't remember if there was a setting for this issue, but I will check tonight. I believe the behavior of the car is just changed with no setting to support the change. Again, different GM cars may Implement this on different model years and different software versions may adjust this within a single model year. I do not have a denali to check this.
2. When you leave the car with the engine off and the key fob is left in the car. It will honk depending on the setting. The car may get confused if you have two fobs. One that left the car with you and one that stayed in the car. The screen shots address this concern.
I don't have the triple honk on either of your examples. The very first day I had this car I disabled the alert. In my 2016 XL Denali this is the menu sequence: Settings > Vehicle > Remote Lock, Unlock, Start > Remote Left in Vehicle Alert