Lets dissect these precons, going over deck themes, reprint quality, and new additions to the Commander format
Chapter II protects you from early aggression, and Chapter III should draw you at least two cards and potentially more (say, an opponent is playing mana creatures)
Plus, its an evasive lifelinker, so it can trigger itself whenever it deals damage
Blood Rite The Vampire deck stands out to me as the most relevant to supporting its corresponding type in a Cube, with meaningful support up and down the mana curve and notably offering some cheap white Vampires, which we really only see on Ixalan
Winter Moon is a lot fairer than Winter Orb, and though I think its pretty reasonable for mono-color decks to drop, the social contract is likely to keep it away from most tables