From news this morning : The "planting evidence" theory can be disregarded as local botanists studied the barnacles attached to the flaperon.This perticular type typically grows on floating debris (normally wood) and the rate of growth is known and from this they declared that the piece was floating from a year up to a year an half.
The IO surface currents alo are consistant with the trip from West coast of Australia to Reunion , as is the duration of the journey (around 18 months ).
So it looks more and more like a match.