As a summary, we can use the current situation. 48.0.2 is a Windows only version (not mentioning useless but this is a different story). 48.0.1 is pushed to GNU/Linux and Mac OS X users and there is no point to propose 48.0.2 to these users. However, we are telling them they are out of date but they can't update. For now, the workaround could be to say that 48.0.1 is the most recent version (or just wait for 49 to be live). In the future, we should do something more clever... Maybe push a v2 of the product-details with "per-platform last version" (even if it doesn't happen that often) https://product-details.mozilla.org/1.0/firefox_versions.json
It would be nice to have the per-platform version support in the product-details API, but once Bug 937865 is solved, Bedrock will no longer require specific version info.