These new laptop lineups seem to be competing in-line with other products in their class. It seems they want to brand their top teir products as "Galaxy Book". They recently released some laptops during CES 2019: Samsung Notebook Flash, Notebook 7, and Notebook 9/Pro. These were probably released to fill the product gap they had with their competitors. The Galaxy Books will most likely represent their best of the best in tech, hence the Wireless PowerShare capability in the Ion & Flex on the trackpad as well as first QLEDs on a laptop.
See related lineups and some of their competitors below:
Samsung - HP
Galaxy Book Flex - Spectre x360
Galaxy Book Ion - Spectre
Samsung - Microsoft
Galaxy Book S - Surface Book 2
Galaxy Book - Surface Pro
Galaxy Tab S6 - Surface Pro X