I've seen this mentioned a couple of times on here recently (in terms of it being potentially attractive to purchasers who might consider MMD as more 'mind clean' from a ethical point of view, IIRC) so it's interesting to see them making a thing of it.
I guess all stones are ultimately traceable through the Kimberley process but I also guess it would require blockchain or similar to ensure that a stone is the stone it says it is, if it is not laser marked!
(You should ask to move this thread to RT - seems a more appropriate place for it! )