My dealer also forgot to give me a spare key for our XUV, but I specifically asked when I bought it. They seemed slightly surprised that I cared but willingly got me another key, pointing out that it is the same key as any JD mower. It isn't the same as my JD 5210, I don't think.
I would definitely ask your dealer for another set of keys as I think this was an oversight on their part.
BUT, if you ever needed a key, you could just go to the dealer and get another one. You wouldn't need a locksmith, etc.