As for your question about why Athearn released a Genesis EMD F7 with a decent paint scheme, it’s possible that they were simply testing the waters to see how well the model would sell. The F7 is a popular model among model railroaders, and Athearn may have seen an opportunity to expand their product line by offering a high-quality, detailed version of the locomotive in a unique paint scheme.
It’s also possible that Athearn was approached by a customer or distributor who was interested in purchasing a custom version of the F7 with a specific paint scheme. In some cases, model train manufacturers will produce limited runs of custom models for specific customers or distributors.