???Any leather will crack if not properly cared for, shell is no different. As long as one conditions and properly cares for their shell, it will be fine. I’ve got a many pairs that are older than or approaching the age of your example and they are no signs or issues of splitting.
Fine consider yourself fortunate. I recall that example was from a regular poster on another forum. There are no indications that he took care of his shell cordovan any less than you do. And there would not be "signs" necessarily, one day they just split.