It would always count as "wise" to get a camera given a once-over if it hasn't been serviced in a long (or unknown) time. Whether or not that would be necessary? depends on the camera itself and if anything was wrong. A professional, though, needs their tools operating properly and as-expected, so getting them serviced regularly is preventative medicine - although a lot of cameras are getting reaching an age that part-failure can occur at any time and won't necessarily be anticipated or prevented by a service.
I'd only get a camera serviced if the value of the camera was considerably more than the price of the service. As in, I wouldn't get a Nikon F2 fixed, but I'd get a Leica M4 fixed. And I'd only get a camera I wanted to regularly use fixed. ... And there would need to be something obviously wrong with it. But I'm not a professional.