This seems to be a common feature in "found" things in the natural sciences—the actual discovery is years before the publication of the associated journal article or conference proceedings. Until the peer review is done, the scientists are understandably reticent (well, with some notable exceptions) to crow about the discovery. It doesn't say in the article (tsk tsk, Guardian) but I'm betting that the "news" in this is actually a scientific publication about the find.
In some cases, they probably don't want to talk about a recent discovery because then there'll be a bunch of people looking for more mummified remains. The researchers might want to have a nice long look around before attracting a crowd of tourists.
I had the same question, and was hoping someone from the field might comment. It seems unlikely it took two years to extract, but perhaps there’s a long lag between taking a specimen from the ground and being able to certify its veracity?