The spell was to keep him save, locking his powers to prevent him from getting found and blocking his memories of the times he had the power...so far its reasonable, but after learning the truth about his past and knowing of his powers its outright idiotic to still keep him in the dark. Not because of this stupid family drama, but because there obviously are enemys far stronger then a royal vampy and an archwitch together, otherwise they could have just protecting him together as family.
Our current path/plan leads us to every supernatural group in reach and we dont even know who the enemy is. Our suspections about the council may be the logical conclusion for this question, but currently only 3 local factions are clear...the wolves and the orcs want to win us over to side with them in that stupid war, their plotting might be annoying selfish but not outright dangerous and the vampys think we are on the same side since they saved/turned us. We know some witches want to drain us to death, we know the head-hunter wants to kill us as soon as possible and we know humans are fucking greedy bastards and want to destroy everything they cant control. We even need to consider our family, ist fucking rare for vampires to impregnate someone, and then some high royal vampy knocks up a whitch, even one of the most powerful witches alive...
We know much more about our local enemies than we know about the council...and we dont know where they have their spies or if they even need infiltrators, they could just oversee the whole situation and track specific persons with magic. It only needs a little gossip, a few rumors and something slightly proofable or interpretable to stir up factions and wait for them to let it escalate by themselves...
This whole war could be nothing but a planned trap. Everyone prepares for it, everyone tries to get the chosen one on their side of the front and those who search for us just need to wait until it begins, the side dont matters and even if we manage to stop this shit before it starts we will be well known for it in every faction, no matter what, our cover will be blown away and without our memories and knowledge about the real enemy we are fucked...especially if the last seal dont breaks in the right moment, something the witches could arrange...and every group has some witches, so i guess the council as well...for all we know they could even be in charge and let the public puppets dance to their music.
So...blocking the powers and memories is not the reason why i understand the protagonists reaction so well, but their refusal to name the enemy after we learned about it. We told them, tell us the reason or fuck off, they went silent...their choice, their problem. I dont need a family who knows who tries to kill me and stays silent.