I have no idea if Araq has any children but I suspect he would leave any legacy for them. I think this is how much he hates inheritance.
On my own behalf, I dont care much, selfishly, if it is methods or vtables/interfaces as long as it will support some kind of polymorphism because I have not used it in any serious way yet. I'm just looking forward when Nim to stop being a running target even before starting to learn it thoroughly. Sooner rather than later, I hope.