I do hope that Divinity 3 will be as good if not better than D2:DKS :P
IMO it would be practically sacrileges not to make another RPG about dragon knights (whether in Divinity 3 or something else), so Rhode could be brought back to deal with the DKS character or a successor, and associated issues.
well Larian are making a co-op divinity game; Original sin, that as of known will not have dragon knights in it

and personally i would of thought that Rhode would change her mind after you free the divine and stop ygerna, as the whole reason slayers want to kill you is because dragon knights supposedly killed the divine but now he is free, maybe her opinions may have changed, and i hope in Divinity 3 that there will be a quest to resuscitate her yourself as a side/plot quest, but i would like to see her in the next game, and for her to have more of a purpose in the story rather than being thrown aside like in FoV.