The availability is a little different from a normal if. A call like #available(iOS X, watchOS X, *) in tvOS doesn't mean "iOS, watchOS, or the minimum target of tvOS", it's just "the minimum target of tvOS". The compiler picks the relevant specification from the list and discards the rest, so a call without the wildcard would assume that tvOS "understands" what iOS and watchOS are, which is not how it works, so I don't know if that's what we should go for.
But this is a little tricky now because we're now approaching it from a readability point of view, so anything could be deemed correct if we think it could work.