The whole point is not whether Jesus had a brother or a cousin but if that bone box is written by someone who was considered his brother and was called so, even if they did consider him a cousin but back then called him a brother.
It deserves more investigation as to whether that is genuine or not. I don’t know if they can provide those answers with any technology. If the patina was disturbed in a prior investigation.
The box is not “the whole point” in this blog since there are at least seven posts dealing with the issue of whether Jesus had younger brothers and sisters or whether those described in Scripture are his cousins or children of Joseph from a previous marriage, etc.