A few companies, including Nikon and Adobe, already announced their withdraws from the 2020 NAB show due to the coronavirus (COVID-19). As of today, the 2020 NAB show is still happening, but I believe this will change very soon. From NAB’s website:
The Photography Show has been postponed because of the coronavirus (COVID-19). From now on, you can assume that every product and/or event will be either canceled or delayed. Here is the official statement from The Photography Show: