There's actually some long-standing document and archeological evidence for this, but the recent DNA analysis makes it all the more likely. If it's true, it would solve an interesting two-thousand year old historical mystery about a Roman legion that went missing in action in what is now Turkey around 50 BC.
A Roman Legion in China | Historic Mysteries
This is also one of those reasons that I am such a fan of World History. This school of scholarship focuses on long-duration systems or geological settings like the Silk Roads or the Atlantic Ocean Basin, rather than just single cultures or nation states. Doing so not only reveals new historical dynamics, but also highlights just how interconnected the world is.