Shun's website doesn't mention the issue. I'd guess, on that basis, that they do not have a full tang. So many western knife buyers are het up about this issue that if they did have a full tang, I suspect they'd advertise it as a selling point.
It really doesn't matter. If you're dealing with a serious, reputable knife-maker, the blade can be perfectly well seated in the handle without having a full tang. What you don't want is a short "rat-tail" tang badly seated in a soft handle. The knife-makers who do this are cutting costs by using less steel in their knives and hiding it with the handle. That's not the case with Shun, and as far as I'm aware it's not the case of any other relatively high-end knife-maker either. So long as the blade will not come unseated, full or partial tang doesn't make any difference.
Top-end Japanese knife-makers have used partial tangs for some centuries now, and the blades don't pop out. I know it's a traditional thing to worry about, and I myself used to think it was a crucial point, but it's not.
Don't worry. Those knives will be fine.
My only other remark is that once you start buying more knives, try another Japanese maker than Shun or Global. Try Togiharu, Tojiro, or somebody like that. You'll pay for it, of course, but I suspect that once you get the hang of it those Shuns are going to look pretty sorry for themselves.