The sort of "untyped" that your last sentence is referring to is a dead term, though. The only "untyped" language still in common use is assembler, and that's not commonly written by hand anymore (and when it is, it's primarily running on numbers, not complex structs and complex values). There aren't any extant languages anymore that just accept numbers in RAM and just treat them as whatever.
So increasingly, this objection is meaningless, because nobody is using "untyped" that way anymore. The way in which people do use the term, Python is only "optionally" typed, and a lot of real-world Python code is "untyped".
There's lots of programming languages still around with untyped elements to them. Javascript is one of them, with its string/number conversions and the way arrays are defined. Then there's all the stringly typed stuff. Make, CMake, Excel, TCL, bash. You're probably right that the original use of the term came from assembly vs. high level, but that objection is meaningless, because nobody is using "untyped" that way anymore....
What makes changing the meaning of "untyped" extra confusing is that dynamically typed programming languages often have types as 1st class objects, and they get used all the time for practical everyday programming. Calling these languages "untyped" is just wrong on the face of it -- they're full of types.
I could even argue that Asm is to some extent typed. Depends on the processor, but some cisc have operations for different types. But also the comment is correct: Python is strongly, dynamic typed.
I think the objection is to the conflation of strong/weak with dynamic/static and it being unclear exactly what typed/untyped means, since it can refer to either. Python has always been strongly typed at runtime (dynamic), vs say JavaScript which is relatively weakly typed at runtime.
Obviously lihaoyi was referring to static/dynamic when they wrote untyped (as made clear by the reference to type annotations) but kstrauser is objecting to using the term "untyped" since that can be interpreted to mean weak typing as well, which Python is not.
$0.02 anyway.