The only really canon things about Plagueis are that he was Palpatine’s master who was allegedly killed in his sleep by Palpatine himself, and that he did research into the force to create, manipulate and extend life. It’s heavily implied that he was sort of Anakin’s surrogate force father but that is no way confirmed in canon. Even his EU appearance and species is not Disney official canon. To be honest the story of Plagueis is one of the best things from the prequels so I’d be pretty happy honestly if they brought him in, as long as midichlorians are never mentioned (which I don’t think JJ would do in a million years judging by his comments)