It depends on the angle of the shear blade. Professional PCB shears cut almost all the width at once so there is very little twisting of the material before it is cut. Sheetmetal shears or laminate flooring cutters cut more gradually (to reduce the required force) and will leave visible delamination a millimeter or so in from the edge.
Even with a professional shear the edge is not as nice, smooth, and square as a milled or sawn edge, but perfectly adequate for most applications. I always used to sand or file them to remove any rags.
ST