I haven't witnessed it, only read about it. But I doubt it will make much difference one way or the other, given the overwhelmingly loud noise made by all kinds of dietary "experts" advocating low fat. WF telling people to eat vegetarian and low fat is unlikely to make much impact in relation to that, IMO.
I don't shop there anymore, either. It used to be a good place to go every now and then to get some things I couldn't find anywhere else, but the last few years they mostly don't have those things anyway, or other places more convenient and less expensive also have them. The last few times I was in there, I noticed and was very annoyed by the fact that most of their fresh produce isn't even organic now, and you have to be careful and really examine the signs to tell. Seriously, less than half the produce in the WF nearest me was organic last time I was there, and we're in CA for Pete's sake, where you can find organic anything, most of it from in-state. No excuse to put conventional broccoli crowns for sale right next to organic broccoli (with stems) for the same price. I won't even get started on the animal products. The only redeeming thing is that here they sell raw milk (not that I buy it there).