I'm sure the swingarm should have no play at all. The bearings are well protected on these so they don't usually fail. In fact, when mine was removed they were looking as new as the ones I were about to replace them with. With that in mind, it might be worth just making sure that the fasteners that hold the swingarm in are done up the way they should be. There should be a procedure in service manual for this. IIRC you first tighten something that presses against a bush to a relatively low torque, then you tighten a nut to fairly high torque to hold it in place properly. You need a special tool for this, but it's an easy job. You'd want to have the back wheel off the ground and unloaded if you can, centre stand is ideal for this, not a paddock stand though.