Just to bump this thread with some additional information and add some keywords. It appears as though either one of two things happen with the 27UN850:
1) LG renamed the 27UN850 to 27UN83A
2) The 27UN83A is just the same monitor, but sold for a different audience (business vs. consumer)
I purchased both the 27UL850 and 27UN83A from Amazon Germany last week, they are the identical monitor (even Mac OS only can identify them as "LG HDR 4K"). The specs are the same from all the websites, the control structure in the menus is the same, and there's nothing in the monitor that distinguishes one from another. I sent the 83A back, since it was €100 more with no perceived value.
The only actual different is the stand. The 27UN850's base is a bit narrower (the curve is a bit tighter), and has a different key to mate with the base. Otherwise, there is no real difference or need to get the 2020 model.