In February 2019, at the Integrated Systems Europe (ISE) tradeshow, LG Electronics launched its 55" transparent touch-enabled OLED displays. The displays are not available commercially yet, but LG seems to be advancing and we now know the first such display model number - the 55EW5F.
We still do not have the specification of LG's first transparent OLED signage, but the company latest prototype shown at CES 2019 featured a transparency of 40% - so we can assume that these new commercial displays feature the same transparency. It is also likely that they are touch enabled (that's what been shown in previous trade shows).
LG Electronics demonstrated this display yesterday in a trade show in China, you can see the new model number in the video below.