Like many a Legendary movie before it, Kong receives a tie-in comic. To be quite honest, these things have seemed a bit superfluous, but this one seems to have a nice hook: a return expedition to the island 20 years later that brings to light (flashbacks? investigation? asking one of the natives?) events before the movie, explaining how Kong became king (I suppose, how he became the last one).
They've even whipped up a trailer for it:
http://ew.com/movies/2017/04/07/birth-o ... ll-island/