It's not about katsumi or olivia. It's for Kane could be the next alexander and these words could be the best encouragement for evil dom players. Concentrate on words, not on girl.
Nevertheless, imo, we should not be misled and associate these words of Katsumi exclusively with the "EvilDom" route, which, moreover, has already largely ceased to be so. Her words about Z5 applies to "any" DomKane, even one who is not openly evil, but one who had the determination to accept Katsumi's offer to participate in the show as a co-host.
It is also true that there is no problem in choosing the “new evil route” (Juliette + Dominique+) and having only 7 evil pts, with the rest being 20+ good pts. Yes, these points, as we know, are not as important as they should be, but nevertheless, for such a “gray Dom Kane” walking this path, good decisions are still available
(and do not contradict the moral principles of both Kane and Olivia), just as evil ones are...
Therefore, I perceive Katsumi's words more as her own desires. Yes, with enough persistence, they are quite achievable, she has no reason to lie, but in my opinion, obtaining the "Z5 Chairman" rank does not necessarily mean that DomKane must inevitably turn into a monster like Alexander was.
BTW, as far as I know, Alexander himself, even at the height of his reign, was never Z5, but only Z4, like the other members of the Board.