In System Image Utility, a tool for creating OS X images to install onto other computers, the 2016 12-inch MacBook is listed as an option when limiting the install image to select Mac models.
In OS X Server, you can choose which Mac models should have access to a NetInstall image. The 2016 12-inch MacBook is also listed as an option here.
Notably, Apple is rumored to be shipping new ultra-thin 13-inch and 15-inch MacBooks in June. It's possible that the 12-inch model will see an update at this time as well. However, the 'Early' rather than 'Mid' designation could mean that the MacBook will be updated even sooner.
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