Illinois extension has a post on the cottonseed issue. As it says, in greater detail than I have the brain cells to waste on, it's complicated, involving both the base acreage/"generic base" issue and WTO. From the conclusion:
Much depends on the final details of any Congressional response but
cotton farmers are currently receiving significant assistance from the
2014 Farm Bill and adding cottonseed may provide a windfall to them,
including one recoupled to cotton planting decisions. Congress, if
considering adding cottonseed, may also have to consider further
revisions to the 2014 Farm Bill such as precluding payments on generic
base acres for any covered commodities planted on them.