What did I skip? Other way around! Yes, there was the grammar included in the TP manuals, but that does not mean that it was used. (And the syntax diagrams is a reference to our own manuals).
Not TP but D5-D7, and that WAS used. I was there, you know that. I may have forgotten that: Borland used almost always internal tools, also for their flavor of BNF.
E.g: Their IDE parser was built with it. Not after it.... You can ask anyone who was at Borland at the time. They will confirm it.
Note: as I said before, I did only "minor" work with the rtl/vcl and analysis.
But it is definitely a case of the programmers left the parser in the dark.