It's my understanding that in the past the Duke of Beaufort has refused dna testing, now with the finding of Richard's remains several members of the family have agreed to testing. I think 4 of them have agreed to the testing to obtain what would be the Plantagenet Y-chromosome. That should match Richard's, if they can get the dna and would also match his nephews. Too bad the church and the Queen won't allow it.
It's my opinion the bones in the urn aren't the princes. After all they were found 10 feet deep under the stone foundation for some stairs. Who would be able to dig that undetected?
Maybe when Charles is King things will change and we can find out.
T