For the longest time the resorts, except for the 2 Port Orleans resorts, WOULD toss any faxed room requests. The Touring Plans fax service is somewhat new, starting within the last year or so. They must have struck an agreement with WDW as their faxes are not just tossed.
So some folks are going off of outdated information. But that information was accurate not too long ago.
On this subject I still prefer calling in our requests. When you do that the request is included within the details the room assignors get. When faxed the requests are a separate sheet that had to be physically matched and then attached to the detail sheet. There's a chance they could get separated. Although slim, it can and does happen.