My bike currently has the exact same leak. I've put a bit over 1 grand on it with the leak. It has gotten a touch worse, but nothing crazy yet. Just bring some extra oil and make sure you keep that topped off. There is no 'gasket blow out' with these.
Its basically a free floating metal collar on the counter sprocket shaft and then a rubber seal that goes around that between the collar and the engine case itself. There is also the oring, but whatever.
Anyways, there is no real catastrophic failure with this besides running out of oil and blowing the engine.
The actual repair takes about 1 hour. No biggy.