That isn't what you were arguing earlier though. You have been arguing that nullable types are *always* a bad thing (in a grandparent to this post) and there is *never* a need for them (to paraphrase several other comments of yours).
To my mind, having to go from checking the value of a reference to checking other properties of a composite object (the type, or a length attribute), and still being left open to runtime-exceptions (with a different name) if you forget, means you still are facing fundamentally the same problem.
Can the compiler maybe catch a couple more problems it wouldn't otherwise. Sure. Is it a silver bullet? Sadly, still no.