I don't say this to be glib, because I would never wish any player to be injured. But I do think the impact for the Nats is negligible and almost makes things easier. The Nats were purely playing a game with his service time so they gain a year of team control, and now they'll get it without having to go through the bad faith exercise of keeping him in AAA where he doesn't belong.
So while it stinks that he was injured, at least it happened during a half-season he was destined to be wasting anyways.