There's no "special Flash installer". I think you're talking about the Plugin Finder Service, which is generic and works with any plugin. PFS serves metadata that points the user to the vendor's plugin download page (possibly to a streamlined installer built by the plugin vendor): https://wiki.mozilla.org/PFS
The "special Flash updater" detects if the user has Flash installed and is out of date, and only if so, it points them to Adobe's website to download the latest version. This is likely to happen for all widely used plugins. Flash is the first because it's so widely installed. More details here: http://blog.mozilla.com/security/2009/09/04/helping-users-ke...
It's pretty easy to find this all out with a search engine, so I'm beginning to wonder if your "slightly incorrect" claims are deliberate misrepresentations. I'd question your agenda, but honestly I don't care. The facts are available for anybody with a search engine handy.