Just my two cents, but in last year or so, perhaps it was in the interview he did with Bruce, Larry Carr had cast a lot of doubt on the FBI's original partial DNA that they had derived back in the early 2000s. (even though we know that they were using it for quite some time to eliminate some suspects)
This leads me to believe that they have recently conducted new DNA testing, whether it be on the shroud lines, the tie spindle, perhaps the hair slide, or something else and they now have a much better result, perhaps a full profile ?
In addition, I wonder if they were able to compare the new DNA result to the older partial and perhaps determine if it is congruent or not ? That would be really interesting...
Based on the recent news that McCoy's son has given a sample, I guess this implies that they never tested McCoy's DNA against the original partial DNA profile they had back in the early 2000s ?