LG Electronics on their latest answer about the benefits of LG WebOS 4.0 platform at this time January 2019:
LG WebOS 4.0 is focused in the connectivity formed by a Smart Home enviroment, IoT Internet of Things, AI Artificial Intelligence Assistant and voice recognition for voice commands.
LG WebOS 4.0 strength goes beyond Smart TVs connection only, but goes to connect other LG devices using AI technologies and is also applied to home appliances such as digital signage, beam projector, refrigerator and washing machine and was scalated to other Smart Home Appliances.
The LG WebOS 4.0 version is running with 2018 WebOS Smart TVs.
There is no news about an upgraded version from LG WebOS 4.0 and we are supposing the 2019 Smart TVs models will be still running 4.0 a little longer.