No they don't. Template instantiation happens during compilation, way later than the preprocessor.

Not really? They're part of compilation and obey all the type rules & syntax of the language. They're not textual replacements that run in a distinctly different phase like macros are.

where in hell did you learn that, this is entirely false

Well, it is today.

When I first learned C++, using cfront in the late 80's, lots of the language was implemented as C pre-processor macros.

maybe lots of the language, but not templates. Cfront 2 did not have templates, and Cfront 3 did have them without using the preprocessor.

You can even check out how it was done: https://github.com/seyko2/cfront-3/blob/master/src/template....