Honestly, this is my take on it. Kakao wants to export their comics and novels to the US / the west, so they bought out a company similar to theirs that currently has the biggest success. No brainer.
With all due respect to all creators (myself included), I don't think they give a damn about our free stories. It's nice to have them here to attract more readers, but that's it. The idea that they're secretly after the rights to however many thousand underperforming series is a bit ridiculous. Things will, most likely, continue as they are for free stories; and yes, that includes little to no visibility or opportunities besides staff picks. Not sure if it means we'll see an increase in imported series and a decrease in English originals, Premium and Originals-wise, however.