I know it's exasperating working with unsourced profiles. However, contacting the project manager is certainly the way to go. It might even turn out they've just linked their unsourced person to your family line and it's not even the same person you're working with.
All sorts of things will happen, but sometimes the other WikiTreer will surprise you. Once, I was certain I was annoying the dickens out of a profile manager (we went back and forth, back and forth) and he actually awarded me a generous genealogist badge.
Best of Luck.