Query example :

CREATE (n:Person:Kebab {name: 'Chardlie dSheen'}) return n

creates a node with label Person:Kebab but on old engine it errors.

I personally think it should error because in cypher it's not polymorphism (where order of labels make sense), it's multilabel, so if you want to do a match/search later, you'll have to keep the same exact order, and subclass match won't work.

In my opinion it should throw an error.