Part request: "Shupp XXL Train Wheels" (Third Party parts)

[Eugen]

Typically non LEGO vendors will share LDraw files if they feel it suits their business. 

If someone wants wheels or track links  or whatever, they can ask the people selling for LDraw files. There are too many missing LEGO parts to even start down the rabbit hole that is 3rd party parts.

I'm talking about opposite direction: when new LDraw user grabs fresh update of LDraw Parts Library, and then found that included Third Party part would fit better for their MOCs, they may then decide to find and buy this part from original seller on the market to build real LEGO model for the MOC.

I suppose not all Third Party manufacturers, which bricks are acceptible by the new Third Party parts Policy (https://forums.ldraw.org/thread-28445.html), could be known by the new users of LDraw.

And again, and finally, I declining my request for the making "Brick Train Depot" parts for LDraw Parts Library, according to your decision as an author of original bricks design to not make it included.

No. In the case of an author releasing CC BY 4.0 parts on their own, they still cannot be added to the library unless that author agrees to our Contributor Agreement. Public domain files can be added under CC0.

TL;DR: If you didn't author the part or you didn't derive the part from an authorized source, you cannot submit it to the library.