LG Display announced that MBC Studio will adopt the company's transparent OLED screens in its Korean 2020 election result broadcast tomorrow (April 15). In February 2019 LG Display started producing its 55" FHD transparent commercial OLED displays, and LGD says that this is the first time its transparent OLEDs will be featured in a high rating broadcast (but this isn't so - see note below on DR1's June 2019 broadcast).
LG Display's transparent OLEDs feature a brightness of 150 cd/m2 (peak white brightness of 400 cd/m2) and a transparency of 38% and a color gamut of 120% NTSC. The display can optionally include touch functionality.
Update - it turns out that Danish National Broadcaster DR1 already used an LGD's transparent OLED display at the Danish election broadcast in June 2019, see video below: