This is a move strictly for the minor leagues as Maxwell is likely still behind Greg Golson and possibly even Colin Curtis on the depth chart. Maxwell is an upgrade over Parraz at least defensively which is likely the point of this trade.
Losing Olbrychowski isn’t a big loss either. He is essentially an organizational pitcher who didn’t have much of a chance of reaching the majors. It’s likely that he would have just been released eventually.
Maxwell has played in parts of three seasons in the majors for the Nationals. In total he has played in 122 games over 219 at bats. During that time he has put up a .201 batting average and a .698 OPS.