You could infer all of that from Roth's words. But he wasn't sincere, imo. I think he went through that whole charade about giving pieces to this one and that one to provide an alibi for the imminent assassination of Michael. In front of a bunch of witnesses, Roth made it appear that he was planning a well-thought-out, orderly transition of his empire to his heir-apparent. So, if Michael turned up missing or dead, Roth could say, "Who, me? Why, I loved the lad like a son. Just the other day, I anointed him my successor...just ask all those sterling characters who were at my birthday party!" What about the Lakeville Road Boys, Eddie Levine of Newport, the Penino brothers, and the people back home whom Roth promised pieces of the action? He mentioned them, imo, for two reasons: First, to show he'd carefully thought through his succession plan (reinforcing that he had no motivation to kill Michael). Second, to spread suspicion: If Hagen, Neri, Rocco or another Corleone ally came looking for vengeance, they might think that one of the people slated to share Roth's empire with Michael got jealous and greedy, and whacked Michael. Clever fellow, Roth!
I have to admit, plawrence, that it hadn't occurred to me that Roth might have tried to wheedle money out of the other guys for the privilege of sharing in his empire. That'd be even more clever.