In all seriousness, I doubt this plot line is going anywhere. The anime can’t stray that far away from the games. They can’t retire Cynthia no more than they can retire Lance, Steven, Wallace, Cynthia, Alder, Iris, Diantha or Leon without due measures and permission (aka the games).
It creates a continuity error if Cynthia were to appear in games later down the line like she does in BWBW2 and SMUSM.
More than likely she’s lose and Ash will be the first person to beat her in awhile and she suddenly has interest in battling again
All of this because Ash raised Lucario from an egg so he’s equal to Garchomp. Poor Noviern has been jobbing since out of the womb