Having a hard time following your post, I dont think "tooling" means what you are using it for. If there was a textured bottom as described, wouldn't that be the result of the "tooling marks" left behind?
Tools are used to make the molds, the molds are then used to make the discs. If you leave tooling marks behind on the master mold, it will result in a textured or gritty surface on the product (disc) from the tool imperfections.
If you switch up tools, or tooling techniques, then you can clean up the mold. Better, newer tools will have better results when making the mold. So while the mold remains generally the same shape, it can have some minor differences based on improved tooling/machining of the mold. So if they got rid of the tooling marks on the mold surface, they would have a smoother finish on the molded disc.
Basically I think you meant to use "tooling marks", as there are no tools in molds.