Not exactly, but there is a way.
h = rectangle('Position',[0 0 2 4],'Curvature',1);
g = hgtransform('Matrix', makehgtform('zrotate', pi/6))
h.Parent = g;
xlim([-5 5]); ylim([-5 5])
Watch out for where the origin of the rotation is; if you want to rotate around the center of the object you should use a transform that subtracts the centroid, does the rotation, and adds back the centroid again. You will find that in practice the makehgtform() call for that will have the addition first, then the rotation, then the subtraction -- that is, the order of operations works out to be right to left.
