Since we have not only established the authors' commitment to detail, but our own too . . .
[Not only do spoilers and speculation continue, but are explored beyond reasonable measure]
There are a few things that have unlike escaped the authors' attention, so neither should they escape ours!
First, having brought up Io, it behooves us to consider Europa, who was brought to Crete by Zeus in the form of a white bull and purported mother to King Minos! That makes three different god-touched white bovines (Io, Europa, and the lurching bull-father of Asterion) that could have some role to play in the story of how Asterion arrived in his particular predicament.
Second, while Asterion reports (along with mythic reception) that his father was an "ordinary" bull, besides simple deception, illusions have been established (the passports), and he also mentions that it may have had some effect on his mother, Pasiphaë - myth suggests that direct contact with the divine can have . . . permanent effects. (RIP Semele). Now, it's also possible that King Minos was in fact Asterion's father, and was in fact a minotaur too, but couldn't openly live as such. (This would also be a great opportunity to explore Asterion and his family's ethnicity as Minoan/Mycenaean/Phoenician/Colchian and the influence of having a mainland presence on Crete and in Knossos - I mean, his name is Asterion, which would have to be a Mycenaean {early Greek} name, and the minotaur motif doesn't appear on sealstones until the Mycenaean occupation, but I won't develop this any further than this windy parenthetical apophasis/praeteritio.) So maybe Asterion's father is mortal (man, bull-cum-man, bull), but . . .
Third - and this is an interesting one - Zeus as Zeus Xenios. He's the god of hospitality, travelers, and strangers. This is concerns a bedrock (yeah I'll get to the bedrock later. Actually, no I won't. The bedrock could be crystalized ichor. Which could also imply some other things but not now) concept of the visual novel, folks! One of Zeus' major responsibilities and purviews is philoxenia, or xenia, which, ostensibly, is a core Minotaur Hotel theme. Look, Zeus comes with a lot of baggage. Is he philandering? Is he selfish? Is he overfond of being over-generative? Is he petty and puny? Is he the possible syncretistic bridge between a much, much earlier myth tradition as represented by the "titans" and meant to be the patricidal god figure that unifies myth-history in the Aegean basin? Perhaps! But besides already showing a close affection for and as white cows, besides being Very Important on Crete - not only born on Crete, but tradition on Crete also purports that he lived as a mortal on the island and died there, too - besides having sent Hermes to slay Argos Panoptes that he may recover Io (and could in some part explain Argos' enmity and exaggerated piety), besides all those things regarding Zeus' comportment; Asterion has been running what is essentially a cult to Zeus for a very long time now. Whether or not that signifies future incursion of Zeus into the realm, that the line of minotaurs mentioned in Hades' are direct descendants of Zeus, or that Asterion himself is a son of Zeus, is hard to tell. Which is good! Discovery is titillating! (Okay, Posiedon could also be in that family tree, but one god or so at a time, please)
Okay. Last one. If Storm is related to Asterion in any way through a line of hemi-demi-semi-divine minotaurs (anthropomorphic bull men but I already suggested that minotaurs are possibly related to Minos maybe so there could be more than THE minotaur), it's possible that - Storm's eventual presence in the Labyrinth may allow P to manipulate some rules, and it also could be something foreshadowed by Asterion's fear that freedom is only possible by trading one's shackles to someone else. (He did say that, right? Am I misremembering?)
That's it for this installment of Wall Of Text™!