I get what they are trying to do with the word "pull", but I'm not sure I like it. Could direct the skier to do the wrong thing. It also seems you are mixing two concepts together here, both tipping and pressure. The topic of the thread is about pressure control. if you want to use "pulling" as it applies to pressure control, than I could see pulling the inside ski in order to remove weight from it, but not pulling on the outside ski.
You should not be trying to push or pull on that outside ski. You should simply be "tipping" it. And actually, there is a lot to be said for not even doing that to the outside ski, but rather focus your attention on the inside ski and your COM. If you focus on tipping the outside ski, there could be a tendency to knee angulate, to smear the big toe by trying to push on it, etc..
Many people have pointed out the idea of pressing the sidewalls of the ski into the snow, rather than pushing down on the big toe. And particularly they have pointed out the idea of doing this sidewall tipping/pressing with the inside ski on the Little toe side, rather than the outside.
Developing edge angles really depends on how you orient your COM relative to your skis. When you try to edge more by pressing on the big toe or cranking that outside ski sidewall by tipping it, then you may introduce knee angulation, which is weak; unless your COM is in the right place. Focus on the COM and just let your outside leg by a firm and strong support, like a tree trunk.
There are a number of ways to get good movement of the com to the inside, including inside ski tipping to the LTE, OLR, ILE, etc.. As your COM moves inside, the edge angles will develop. If you are using good mechanics to get there, have angulation, etc., then outside ankle will evert by itself and you will have a good edge developed that pretty much all you have to do is stand on it at that point.