There is very little to service on a wing. If you get the kind that uses the generic inflators, you can service them or replace them for about what it costs to have someone else service them.
It can happen. Wings can develop small leaks due to manufacturing defects, stitching/seams can come apart, etc etc. Granted such problems are rare but if it happens you don't want to miss you wing for 2 months because you had to ship it back to Europe to get it fixed.
Case in point. Was it about 10 years ago that Halcyon had that inflator recall? The the poor slobs who bought Halcyon wings over here were screwed. It was either ship the wing to the US to get it fixed, or replace the inflator with ... I think most people used the generic one that Diverite uses. Too bad really, because many of those guys who bought the Halcyon wing really liked the bling-bling inflator.
So yeah.... rare, admittedly, but not unheard of.
R..