Where they went is as important to a lot of development as who they were. The Firstcomers will show up again in two more essays already completed and in the queue. (The Yaheetes and Tyrus: The Wars Against the Hand and the Eye in the Sheldomar, and The Rhola and the Toli: The Battle For Jeklea Bay.
Gary has also suggested as a title Beyond the Olman Isles: The Explorer King in the Densac Gulf, for a future essay which will include more information on the Firstcomers in the Pirate Isles. Whenever we get around to writing it that is. :) Bit I wouldn't expect that to be done in less than 2 or 3 months, as it is not a topic I've given much thought to, so it will require a lot of input from Gary.
(For those who don't know, while I write the text for these, Gary provides certain specific events and concepts to be included, as well as reviewing the general text, along with Dethand and Duicarthan, and whoever might be lurking in the Greytalk chat room at the time.)