The changes made it a bit harder, but it's still possible with the same strategy, just with more resets and a few items (or insane RNG). I've beaten her again in v6.
I don't know if her Yveltal still spams Sucker Punch in the beginning or if it is changed to Oblivion Wing, but if not, I took down two of her mons. I was very proud of that.
Her Yveltal uses heat wave, zen headbutt, oblivion wing and dark pulse now iirc - for me though the most annoying change was that there was hail during the fight.
