The danger here is asking a native English speaker their opinion when it could be a very cultural distinction. A U.S. dictionary will unambiguously call it a sandwich, but that could be simply to facilitate explaining what it is to a less familiar audience; essentially ”it’s a sandwich with these unusual characteristics”.

We also have “hot open face sandwiches” though which is typically a single slice of cheap sandwich bread topped with hot sliced meat (usually turkey or roast beef) and hot gravy.

But if you want my opinion, yes - they’re all sandwiches (albeit non-traditional).