The process to generate these was opaque, so there was some concern that the values might have been backdoored somehow like Dual_EC_DRBG was; we didn't even have confidence that they were generated from a PRNG rather than some other process. Knowing that the values were generated this way makes it much less plausible that there is such a backdoor.
>like Dual_EC_DRBG was
There is no evidence that it was backdoored.
But you can still analyse the behaviour of the values to identify backdoor behaviour rather than insisting on uncovering the exact method od generation.
Just seems to me like that's quite low on the priority list. I guess this result assures some people that the values are good.