Pre-ceramic GMT II question

[mask1196]

I recently got my GMT evaluated at Rolex USA here in NYC and noticed that the GMTII I have which is a D-seriel that was sold with a 62510H jubilee bracelet has a seriel number - 16710T printed on the evalutation letter. After digging through some of the older threads, I became aware of a comment coming from one of the member here on the forum saying

" ...you all know
that this is the only GMT with the letter "T" after the model
number Ref: 16710 at 12.

Indicating/commemorating (?) the change from steel cases with holes
to steel cases without holes...DEDICATED to the Y serial model year ca. 2003...ONLY..."

What I DON'T understand is how my D-seirel could carry the same 16710T model number if the aforementioned remark is true........

Anyone??