The title is not a very good one, because it's nearly a rhetorical question: no language I've ever seen -- not even Haskell -- has a type system that completely removes the need for tests. For example, even Haskell has partial functions over types like Int whose behavior can't necessarily be encoded in the type system (at least, not ergonomically/practically) and thus require actual tests to cover.
That said, I think a more accurate title for this post (based on the paragraphs beyond the first one) might be "are tests necessary for a view layer that doesn't have much business logic in it beyond passing properties when that view layer is written in Typescript?" At that point, it's really just a permutation of the question "are tests necessary for the view layer of an application?", which has highly-situational answers.
That said, I think a more accurate title for this post (based on the paragraphs beyond the first one) might be "are tests necessary for a view layer that doesn't have much business logic in it beyond passing properties when that view layer is written in Typescript?" At that point, it's really just a permutation of the question "are tests necessary for the view layer of an application?", which has highly-situational answers.