From a fluff stand point am, not sure there should be Primaris Blood Ravens.
Reasons:
1- Ahriman, the Warhammer video games, the books all heavily imply the Blood Ravens came from the Thousand Sons.

2- Guilliman ordered Cawl to ONLY use the 9 LOYAL legions geneseed to create Primaris Marines. (Even though he had samples of ALL 20/21 Primarchs

With those two points in mind, I don't see how the Blood Ravens and any other (currently loyal) Chapter descended from a traitor Primarch would get Primaris Marines. Fluff wise any way.