Hello. After completing the Vault of Braccus and getting rid of the collars I ended with the SJ of Rex's former friends . Question: Is there any repercussion for eating these souls in order to replenish source points?
There is no repercussion besides not being able to use them for a certain quest. If you need to replenish source points, look around some more and you'll find a source fountain which you can use for unlimited replenishment.