This is an interesting theory and would account for why private scripts tend to have lower ban rates.
You mentioned in your first post that anti-ban is "just a marketing scheme" and, for the most part, I would agree. However I do think it can be used as you've described above. When I used to make simple bank standing scripts a few years ago I would include unneeded behaviour in the script just to try and mimicked some of my "ticks" from normal gameplay. One example I can think of are mouse movements towards an object before the need to click on that object; sometimes I find myself pre-hovering the next tree I would cut, sometimes I do not. I am unsure how much data Jagex collects on in-game behaviour, although in this world of big data I am sure it is a lot, but including these quirks in the form of a unique anti-ban does seem likely to help. The problem arises when this unique anti-ban is used by a mass of people; suddenly everyone is acting in a particular way and detection, based on the analysis you described above, skyrockets.