Habarudo said:
Confirmed: https://twitter.com/Yann_Le_Gall/status/787547404123856896

I'm going to remove the artist unknown on the Yuri on Ice OP posts because from the source tweet it's clear that Park did all of the animation and the help he had is closer to 2nd KA adding detail and fixes to the drawings, they're credited as genga on the OP but it's enough to just credit Park on the booru.