In case Mikami is still working and not retired I think they should hire Shinji Mikami for a new game (probably not for RE 9 as that one is gonna be about resolving the cliffhanger from 8, and give closure to the story of some of the classic chars, and from that point (RE 10, or a side story/spin off) will bring a new arc and this should be ideal time to bring Mikami and it's possible he can also choose those who will be part of his "A game" staff in order to set a good course for the future of RE?
In case Mikami is not available, then another choice is picking as partner Playstation/Sony, I think the RE brand was very strong under Sony and many consumers still view RE as Playstation franchise, developers exclusive to Sony that could help create cool RE games, Naughty Dog, Housemarque, Supermassive games, Quantic Dream, Guerrilla Games, Imsoniac Games, Bend Studio, Santa Monica, etc...