When you say "drag" do you mean "suction" or "negative lift"?

Drag is usually the term associated with a force acting against the direction of motion. For lifting foils this is a horizontal force. This would not pull the windward hull down, generally speaking it would just slow the boat down and make it yaw to windward.

If you're talking about suction or negative lift then yes it will increase the righting moment of the boat.