if the load is removed from an eccentrically contracting muscle, will it start contracting concentrically?
Yes, because net force is the only thing that matters. To address @Chris's comment, in an eccentric contraction and a concentric contraction, the muscle is applying force in the same direction. However, in an eccentric contraction, the muscle is not applying enough force to actually lift the load. A biceps curl is a good model:



SportScience

In the second image, the muscle is contracting but not exerting enough force to lift the weight--the net force causes a slow lowering of the weight.


  Rather than working to pull a joint in the direction of the muscle contraction, the muscle acts to decelerate the joint at the end of a movement or otherwise control the repositioning of a load. - Muscle contraction (Wikipedia)


It may be clearer with an actual force diagram:



University of Guelph

The only factor influencing which way the lever (your arm) moves is the net force. So yes, if you change the load (force F in the above image), the muscle could begin pulling your arm in the opposite direction. The muscle isn't really "changing action", it's exerting the same force, but now there's less force resisting it and the overall movement changes direction.

The question in the title and in the body are not really the same question, but the force is still exerted in the same direction as the muscle. You don't "see" movement in that direction because the forearm on which the force is being exerted is fixed at the elbow joint.