WHEN the dealers have begun this recall (not yet mind you), ANY dealer can easily check yourcar for open recalls by running the VIN through what's called DCS. That tells them if that car requires that or other open (not done) recalls.
I can't imagine why anyone would get "rude" about telling you that as it's no big deal. Don't try calling a dealer yet about this as it STILL hasn't begun and there's absolutely no dealer parts or info so far about this upcoming recall. Apparently it's taking longer than originally planned to launch this recall.
Now, once the recall starts and they run DCS on your car, don't get upset if your car doesn't get this recall as it's not effecting every 850. If your car isn't listed, a dealer won't be paid by Volvo to replace the parts just because you might want them to.