No they didn't. Those priests disobeyed their leaders and went of their own accord.
Despite the high elves' official departure from the Alliance, some elves still remain true to their former human and dwarven allies. The altruistic priests of Quel'Thalas refused to abandon their roles as healers and agreed to remain in Lordaeron despite the edicts from their reclusive masters in Silvermoon. The high elven priests use their Light-given powers to heal the wounded and bolster the spirits of Lordaeron's fighting elite.
--WC3 manual
They wanted to go Alliance, but the Alliance fucked them.