Ya, um no. The majority of the issues are related to poor net code, which UE4 won't fix, and horrendous management practices by NCsoft and NCWest. So, yes UE4 will make the game look pretty, however it won't fix the management issues. The game has been on a rocket sled ride downhill for at least 6 months (see Storm of Arrows update) and this letter is more evidence they have no intention of changing that.