That would shock me less than a lot of people I think.
Renan is big as fuck and moves pretty slick and he is aggressive and violent.
Also, and maybe I will get flamed for this but I am not so sure Francis is the age he says he is. I feel like that trick is pretty well known for athletes coming from certain places where it is believable a paper trail could be lost.
Albert Puljos for example.
Francis getting old overnight/chin potentially not what it used to be (a few months after being knocked out COLD for a minute or 2), etc, would not shock me.
Francis coming out and starching this dude in Jahrzino KO fashion would not shock me either.
Big boys.
Whoever lands big first likely wins.