PC Gamer points to a forum post where the CEO and founder of Sandbox Interactive, Stefan Wiezorek, explained in simple terms why the game would no longer be free-to-play... Making the game ready for a free to play model would take up significant development time which we would much rather use to make a better game. Free to play would also create a lot of risks for the game - spamming, botting, world too small, etc - which we do not want to take if it can be avoided.
They put the free-to-play model on hold and will instead focus on selling starter packs, which will be condensed Founder's Packs. Don't fret over pricing models and payment, though. The Albion Online Silver won't see the light of day for a long time given that closed beta testing is expected to run all the way through 2016 to August 1st. After closed beta testing is completed the company will then launch the title into open beta.
They actually have a lot of plans for the game in their 2016 roadmap, including significantly increasing the game's world size. Diversifying the city and zone hubs to be more unique and make players by Albion Online Power Leveling feel as if they're actually traveling around to different locations. Different biomes, presumably with different resource gathering opportunities per biome. And they have plans to completely rework the PvP system for reputation and crime – players who continually player-kill will eventually be labeled as a criminal.