Before the most recent iteration, Minerva's had to fight Urzkartaga as much or more than Diana, but I can't think of a single mention of him since she started wearing those pants. Something's got to explain how he disappeared, and "she flipped out and ate him" ties that up as well as explaining how she's on more solid (and independent) footing, powers-wise, than ever before.
Also revealing that now, shortly after Athena has died of sorrow from learning Diana signed up with that Polynesian guy, strengthens the symmetric rival deal they have going. Also Circe would give her props and respect (<"i>That's</i> how you deal with troublesome men!" she'd say) that she hadn't previously, so you could build a psuedo-antagonistic peer relationship between them, playing off their past Mastermind/rebellious tool relationship.