Buying an REO property directly from the bank

I was told that one strategy to obtain an REO is to wait and see if anyone bids on the property at trustee sale. If no one bids, it goes back to the bank as an REO. Then, contact the bank directly to see if you can buy the REO directly from the bank before they list it with a broker. Is this scenario valid?
I just attempted to do this today, and was told by the loan servicer that I need to wait for the property to be listed with a broker and appear on the MLS before they will look at any offers. I'm a Realtor, so I also asked one of our top REO listing agents in my office about this, and she said that many of the banks have changed their rules. That they will not sell direct and will require their REO's to be listed with a broker first and displayed on the MLS. Have the days of approaching banks directly to buy an REO, prior to it getting listed with a broker, come to an end?