In the past, we've sent in our request to the room assignor 3 days before we arrive.
Yes, there have been many reports on the DIS about the faxes no longer being reviewed. I just read a post over on the YC & BC FAQ thread and a CM is recommending to a poster that she puts the request on her reservation, but also contacts the resort directly 3-5 days prior to arriving. The question has been asked if a fax is acceptable, but the CM has not responded yet. Unfortunately, I don't know if this is a front desk CM though and this person might not be aware of any recent changes in procedure.
I guess if it's on your reservation and you just follow up a few days prior to arriving, it wouldn't hurt.