Is it? I dunno, honestly. Obviously it's dehumanizing, but is it actually racist? I don't think this counts as a racial slur, it doesn't have the history, but I also don't know enough orc lore to argue. Seems more like a nerdy version of calling people barbarians...
Either way as a Russian I've waited long enough for us to get our own n-word analogue that only we get to say.
The tweet .
To make it easier for them to shell civilians. it's a little like "is it racist to call Palestinians 'sand n******' for shooting rockets at you?"