percy being afraid of thalia and them not getting along really well makes much more sense now because now thalia actually has more incentive to hate the gods, especially her father. imagine your father turns you into a tree to punish you, when it's his decisions that led to your existence, you lose 6 years of your life, you don't get to see your friends grow up, and when you wake up you find one of your friends is actively fighting against the gods AND there's a prophecy which says that you might have to decide the fate of the world in less than a year, by either choosing to go against your father - which would mean going against most of your friends, destroying the only safe places for people like you, and letting your textbook evil grandfather become ruler of the universe, OR choosing to stay on the side of your father - which would mean going up against your oldest, closest friend who was the first person to treat you as a person and not an otherworldly being or a mistake, and it would also mean supporting your father WHO LITERALLY TURNED YOU INTO A TREE AND TOOK AWAY YOUR LIFE AND YOUR AUTONOMY JUST BECAUSE HE HAD YOU. AND YOU DIDN'T WANT TO BE A VESSEL IN HIS WAR. thalia's life is so tragic, any decision she would make was bound to hurt many people in the process, and genuinely nobody could hold it against her that she joined the huntress and took herself out of the situation entirely. i think they knew the prophecy was never going to be about thalia from the second she said no to zeus that day on the hill, and choosing to join the huntress was her way of not having to choose between a bad and a worse option. good for her that she finally found peace in something.