jitter, skew, and latency are concepts that are completely misunderstood and mislabelled. some people call jitter what is actually uncertainty. some people bin all the effects of process variation into jitter... and so on.
what you really need to know is that all forms of jitter, skew, and latency are accounted by the clock tree synthesis tool. your assertion is correct that every cell you add to the tree may create delays with an almost random characteristic (due to process variation).