The technique is good, and compilers that interact with assembly should do this, but as you outline, they basically just shove blobs of text around and hope for the best.

I didn't say you were referring to TALs. Yours is a syntax level check, not type checking of the program in the normative sense. It might be more accurate refer to your technique as an "instruction signature", rather than a type.

I would argue that that are complementary and not entirely different.

I thought it would be interesting for folks.

But a language being “typed” doesn’t tell us anything useful. Untyped languages are typed too: they’re uni-typed (every expression is an expression).

I think you do your analysis a disservice by focusing on “is assembly language typed?” as the top line question. The more interesting question you examine is what do the type constraints in inline asm offer, and how do they interact with the host language’s type system?