But they don't have to reverse engineer the numbering system to find it out. Day one they just get told "here's how the numbering system works. Don't tell the Internet. kthx."
I doubt anyone at LEGO fully understands all of the naming/numbering convention decisions that have evolved over 70+ years.
This is especially valid if you try to add any kind of logic or embed information in the naming conventions, as you'll quickly find out that the number series you allocated five years ago has proven to be too small.
And you can forget about scrapping everything and just creating a new system from scratch; all the documentation and drawings already point to the existing numbers, so the new system can't use an existing number but you have to map whatever you have to the new system... not unlike this[0] xkcd. And this is assuming that you've got loads of money to spend, and nobody cares how you spend it.