I assume the reason behind this is to show her that you have a life and are busy on the weekend nights. And to make her wonder what you're up to, and make yourself look higher value in the process.
I suppose that makes some sense on some level. Of course you run the risk that she will meet some other dude that she likes better while she's out on the weekend nights herself. But according to pickup dogma, you're not allowed to care if you keep her or not ("no outcome dependency"), so who cares anyway, right?
I suppose it sounds like a good idea, especially early on in a relationship or wahtever it is. But honestly, I'm not big on playing a lot of games trying to make her think I'm a big deal. Seems kind of like qualifying myself to her in a way. If I want to go out with her on a Friday night, chances are I will do it and not worry about what "Doc Love" says.