They didn't - last I knew - distribute LAME or other MP3 encoders. I think the patent enforcement situation has changed since that call was originally made, but earlier (late 90's, early 2000's), the patent owners were enforcing patents for encoders but not decoders.
Mozilla has trademark rights over the Firefox name and logo, and they license the logo's image file under a proprietary copyright license. It has nothing to do with patents, so the new policy does not affect that issue at all.