By your measure, that wouldn't be considered source code. The original meaning was somewhere along the lines of "not assembled bytecode".

Why the new term then?

Compiling was commonly thought of as including what we now refer to as the assembling step. They wanted to point out they weren't doing that. Editable code, non-hex code, non-binary code, etc. was thought of as source code.

This stuff isn't worth getting upset over. Defining terms to have reasonable conversations has always been difficult.

Here, if you see compiler or transpiler, you understand a transformative process is happening, and so does everyone else.

Accusing someone of misusing a term that can mean different things to people from different backgrounds, or being "wrong", is just going to isolate you from being able to speak reasonably to them.

Our language evolves. A word from nearly thirty years ago is coming into common usage, which means that it's definition will likely change. It might become even become more specific. Most programmers using transcompilers today, don't have thirty years of experience behind them, but they will shape the usage. You can find a middle-ground with them... Or convince them your experience isn't worth listening to.