That's the pessimistic possibility from an A&M climatologist here.
One of the programs of government programs (and of private corporations, look at GM) is adapting to changed conditions. Texas farmers have eligibility for some program payments based, not on what they currently grow, but on what they grew in the past: 1990's. The last I looked the only way to lower a farm's base acres was if the total of the bases exceeded the cropland on the farm, plus historical doublecropping. So if a drought convinces a farmer to take land out of cropland status he might lose base.
The same applies for yields--they generally are fixed, with little likelihood to go lower. (Not true for crop insurance--their APH is similar to what ASCS had in the early 80's as "proven yields".)