A push disconnect. Sure. Probably what I would call it too if I saw the swing you are talking about. I see it in both boys and girls. I presume this is what these people are teaching. Photo 18 of 31, Analysis
Yes that's a push, but not the push I'm talking about. The push I'm talking about I see in the girl using the Connector device. There seems to be a widely held belief in fastpitch, that a hitter can't push if they rotate their shoulders and maintain the box/triangle.
It would be interesting to see if the Connector device would work doing what BM is doing. I would guess probabaly not. Is there a way to blend what BM is doing with the hand path the girl is demonstrating while using the Connector device? I'm not sure. I'll leave that up to others who have actually used the device to decide.
My experience has been that if you get your hands flat early like BM is doing, the front elbow raises up nicely, very early in the swing, making it easier to maintain the triangle/box. So, I'm not sure the Connector device is necessary if the hands get flat quickly upstream.