I put this theory in the tinfoil hat category, and I scratch my head whenever I see it. I think a lot of people would like it to be true, but this move isn't evidence for it.
I wouldn't say it quite qualifies for tinfoil hat. I don't know about wanting it to be true. I would like to see Wizards do well.
My reasoning for saying that is when they told retailers you can do 3.5 or 4 not both. As incidental evidence I know that two bookstore chains have had poor sales and two FLGS owners I am friends with told me of poor sales.
Having been in big business when you have had a legacy product with huge popularity and a new product that is getting luke warm support you try to kill the legacy hoping it will force the customer to the new product. Sometimes it works, sometimes it doesn't.
There would be no reason whatsoever to take down both the 4e and older edition materials, if they simply wanted to stop selling the older editions.
Actually I wonder why take down the old versions to stop pirating of new stuff. If all the old stuff is so readily available from piracy seems silly. Taking it down now serves no purpose but to cut a revenue stream.
Making PDF's available doesn't really change Piracy. Take a look at Palladium books. They refuse to create PDF's and I just googled Palladium and torrent and it looks like it has almost everything they ever printed.
So if they did this to prevent piracy it was pretty foolish. It looks like they shot the horse to keep people from stealing it. I assume someone there would realize that so I think there is another motive.
Yes, there would have been an uproar about removing the older editions from sale. I can't imagine the uproar would have been larger, though, if they had only removed the older editions and left the 4e materials for sale. You can come up with scenarios where it somehow makes sense if you add on about three or four assumptions, but occam's razor doesn't give me any reason to doubt Wizards' official statements here.
-O
I like using occam's razor. Here I would say removing profits to stop the innevitable isn't the simplest solution.
I am not saying you are wrong. Unfortunately, or fortunately depending on your point of view, we can not know why they made the decision they made unless we were in the room at the time. I was just stating that is how I feel. Not a fact, just a feeling
vsper