I think it is a stretch to say this discovery “adds evidence” that the Shroud of Turin is a fake. What they found had no bearing, really, on the shroud.
If a person died today and was buried inside a piano, would digging up a grave in Cincinnati 2000 years from now and finding a metal coffin have any bearing on whether someone in the US was buried in a piano? All it would prove conclusively is that particular fellow was buried in a metal coffin.
The premise of this argument is two graves with intact pieces of burial cloth have been found from the first century, and neither is similar to the Shroud. Therefore, the Shroud could not have been used to wrap the body of Jesus.
Several questions arise: Just because the Shroud’s weave doesn’t match the only other two examples of burial cloth known to exist, one from a grave known to have been tampered with, what mandates that it has to match to be valid? What says the fabric of the Shroud had to come from (be made in) Palestine?
The article quotes Gibson as stating the weave of the Shroud wasn’t available in Palestine until the middle ages, but textile experts shot this notion of “no textile like that until the middle ages” full of holes 20 years ago.
What I see is an interesting discovery that stands on its own, but doesn’t impact the Shroud one way or the other.