To compensate for the lackluster QLED experience from 2017, Samsung is betting now on the MicroLED technology that seems to better than the current OLED solutions form LG. The First Look panel at CES 2018 showcased a 146-inch modular MicroLED display named "The Wall", which features 8K resolution and AI-based upscaling algorithms to improve the available FHD and 4K content.
https://www.notebookcheck.net/Samsung-s-modular-MicroLED-TVs-expected-to-be-better-than-OLEDs.277218.0.html
The Samsung MicroLED prototype demoed at CES is 4K resolution.
8K mentioned in Samsung press release is for their upscaling algorithm in QLED TVs, it's unrelated to "The Wall".
Due to current technical limitations, 8K pixel density across 146inch is still too dense to achieve.