In some families, in might be like so. In families that are in power, however, you sometimes become all too aware of what your own flesh and blood is capable of.

[Ask him how he knows, haha. Most of the plots he's had to deal with happened because of his own mother.]

However, both Macaluso and Vannozza were very young when they came to be in their grandfather's care, and they probably were already being targeted for one of them to become a host for his soul so, keeping them in the dark was of the essence.

Knowing what we know now, this absolute farce of having them compete for the throne is even more cruel. Don Bonaccorso is shrewd. But I would expect anyone in his position to be.

As for consequences... I would put this very firmly in a box of 'this is not our problem to solve', if I were you. In general, though, keeping some people in place that one would normally excise or punish for the sake of stability is a done thing. The decision, however, should not be ours, but theirs.

It seems to me, however, that you are inquiring about someone specific. And being newly arrive, one wonders why.