The ejector can be converted to a spring driven extractor, but not a mechanical extractor as comes from the factory, the underlug is totally different. There have been some here that have ordered barrels with an extractor instead of the ejector, so I would just request the extractor on your barrel order to take advantage of the barrel discount offer. They won't come standard on any model except the new calibers until they run out of the old style underlug, I'm sure that's what CS meant when they said they won't be available until later this year, that's the same thing they told Mac earlier this year. You may have to wait longer for the new underlug to be installed, but I'd still order it with an extractor now if you want one.
Tim