WMF has had nothing to do with Wikia/Fandom for years (apparently they shared some hosting costs back in 2009). Jimmy Wales also hasn't exerted control over Wikipedia policy in a long time, and as of this year no longer even nominally has the right to overrule ArbCom.
So at the very least that's not actively motivating the continued state of the notability guidelines, though I don't know if it's possible the original motivation was as you suggest.
Yes, and that was what I myself thought as I scrolled past.
"Jimmy Wales also hasn't exerted control over Wikipedia policy in a long time, and as of this year no longer even nominally has the right to overrule ArbCom."
Except these two facts niggle.
He's on the board, and will always be the founder. He is SV aristocracy in a town where the money you earn is less important than the people you know and the things you have built. He will always have influence and it's naive to believe he wouldn't. So, it is not entirely accurate to say he has no control, just less control than he did. Is it too little control? Perhaps, perhaps not.
If I wanted to construct a set of policies that drove traffic to another site, I would make them quite like Wikipedia has now e.g. Wikipedia is not a gamers manual. Then I would target for deletion much of the nerd content, quite like now. This is quite a coincidence.
I'm not attached to this theory. Also, I don't like spreading negativity. But to me it seems at least somewhat plausible, and that possibility disturbs me a little.
So at the very least that's not actively motivating the continued state of the notability guidelines, though I don't know if it's possible the original motivation was as you suggest.