Not convinced.
When the Wolverines bit the dust, they were second- or at most, third-generation Clanners; not to mention the civilian castes who would have outnumbered the warriors by orders of magnitude and may have included people who personally had been on the Exodus. I don't know when the eugenics program really took off, but for all we know the Clan concept was only introduced in 2807 - and I highly doubt vat breeding was already a working process by then. Which is to say, genetically engineered (or even "trueborn") people couldn't be more than between 14 and 17 years old, and there may not have been any at all yet.
That's okay. We can discount whether the eugenics program had taken off by the Wolverine Annihilation and left long-term artifacts (improved mitochondria, absence of common genetic diseases, etc.) in warrior DNA.
The Clans simply wouldn't know what to look for, unless you want to assume the complete genome of every last Wolverine citizen had been saved in some database.
The Clans don't need the complete DNA sequences of every Wolverine citizen. They just need the DNA sequences of some Wolverine warriors before the Wolverines' annihilation.
Unless every record was lost during the Wolverine annihilation, the Clans likely had the DNA sequences of Clan Wolverine's (and every other Clan's) 40 or so founding warriors. And given the eugenics direction that Nick Kerensky was headed in, the Clans probably had the DNA sequence of every Wolverine warrior right up until the Wolverine annihilation.
Even if no Wolverine warriors survived to take part in the Wolverine exodus (which we know not to be true), it is unlikely that none of their relatives or descendants did. Their society was still transitioning from SLDF army to Clan. Wolverine warriors would have had both extended and nuclear families with whom they shared DNA sequences that could be traced back to those warriors. We could do that tracing over a half-dozen generations just using real-world technology today.
I think the only way you get a Wolverine-descended population in the Inner Sphere that cannot be traced back to the Wolverines genetically is if you assume that no Wolverine warriors and absolutely none of their children, siblings, nephews/nieces, and cousins were able to survive the Wolverine exodus. That strains credulity for me. It's like saying that a nuclear "Third World War" not only kills every US serviceman, but every member of those servicemen's extended and nuclear families. Certainly possible, but statistically unlikely.
Regardless, the Clans (or at least the Ghost Bears) have some Wolverine genetic signature that they're looking for among Blakie populations in the latter stages of the Jihad. It must be valid and testable. Otherwise, we have to assume that the Clans' genetic scientists are raving idiots.
Given that the Clans (or Bears) didn't find any Wolverine genetic markers among the Blakies and given that it's unlikely that every Wolverine warrior's extended and nuclear family member died in the Wolverine exodus, it would appear that Parradeu's journal was falsified somewhere along the line and that the Blakist cabal has little or nothing to do with the Wolverines.
(Unfortunately, in my storytelling aesthetic judgment, but that's another thread...)