Aside from Kotetsu/Cameron's who kept its female VA Rikako Aikawa from its time as Riolu, past Lucarios were voiced by Daisuke Namikawa (only the movie and Gurkinn's though, and I feel like they cast him for Gurkinn as a nod to the OG since his was a veteran with a small role, so I don't expect him for Satoshi's), Daisuke Sakaguchi (Sumomo/Maylene, Riley/Gen) and Kiyotaka Furushima (Corni/Korrina, Souji/Sorrel). None of them are in the cast and none of the VA's who are seem particularly fitting imo, Miki maybe but he's already Farfetch'd so that'd be a little awkward imo. Furushima still regularly plays side characters so I'd bet on him. Yuichi Nakamura could be interesting though, I don't think he's voiced a Mon before. Kukui's VA Keiichi Nakagawa voiced Lycanroc so that'd be a funny parallel.