What I want to know is where are the Warriors from the Moreau bloodline? If they're using ELH survivors and Scorpion Empire citizens for new bloodnames, why not his?
Probably for the same reason they aren't already in use
The Clans have existed for 300 years at this point.
The Clans can and do use freebirth DNA in their breeding program. This offers a potential route for the Scorpions to have integrated Moreaus DNA into their program. However, that depends on how strict NKs command was, but if they were able to use the DNA of the ELH and other Spheroids, then NKs command on the issue presumably didn't limit the use of freebirth DNA to just the 600.
One would presume that the bloodlines of many of the original support troops and otherwise important figures in a Clans history could have been integrated in this manner.
The second point to consider is that it is possible for the ilKhan...and presumably, by extension, the Grand Council...to create a new BloodName. While CGL would suggest that none were created in the centuries before REVIVAL, the suggestion that no Clan Warrior performed well enough, or earned enough glory to warrant the ultimate reward is, quite frankly, ludicrous. Even at one every fifty years, that is another four or so BloodHouses per Clan at the time of REVIVAL and given the importance of Moreau, one could presume that the Scorpions would push for the creation of said BloodHouse and might even have been a little lax. You get a Warrior with a Moreau heritage as part of the program to keep the DNA "fresh" who perfoms glorious and you end up with a BloodHouse which can trace its lineage back to Moreau. A little indirect, but still it also has to be said that TPTB have stated (I think) no new Bloodnames were added. It's silly, but there it is.
The third point, which you also mention, is that the Scorpions now appears to have decided to assume the right to create BloodNames. The criteria is unknown, but it doesn't appear to be as strict as the Council of Six Trial of BloodFounding. Indeed, going by the text, it appears more in keeping with NKs Bloodright...the ultimate reward for a warriors' performance, with the difference being that the Clan Council/Khan awards it rather than the Grand Council or ilKhan.
That points to several possibilities -
1: The Scorpions have interpreted Nicholas' restriction so as to forbid Moreau permanently. This seems unlikely, but I suppose not impossible.
2: The Scorpions feel they require Moreaus DNA to create a true BloodHouse and don't have it
3: There is a Moreau BloodHouse, but it is newly established and small.
4: The Scorpions want to create such as BloodHouse, but noone with Moreaus DNA has performed gloriously enough to warrant the award and they don't want to cheat or cheapen the award.
