Here is a new write up about 7nm EUV and Samsung. Scotten Jones thinks it may actually happen with a lot of caveats. In fact he thinks it may be as early as this June.
https://www.semiwiki.com/forum/content/7403-samsung-starting-7nm-production-euv-june.html
"Perhaps in order to get EUV started they will accept low throughput and high costs to be first to production and to start the high-volume learning process.
The combination of what is known about EUV and the rumors about Samsung make me believe that we will in fact see Samsung begin to ship 7nm wafers using EUV starting in June. Likely this will be by running the EUV systems in a way that delivers low throughput and high costs and there may be yield issues as well, but this will make Samsung the first to enter production with EUV."
https://www.semiwiki.com/forum/content/7403-samsung-starting-7nm-production-euv-june.html
"Perhaps in order to get EUV started they will accept low throughput and high costs to be first to production and to start the high-volume learning process.
The combination of what is known about EUV and the rumors about Samsung make me believe that we will in fact see Samsung begin to ship 7nm wafers using EUV starting in June. Likely this will be by running the EUV systems in a way that delivers low throughput and high costs and there may be yield issues as well, but this will make Samsung the first to enter production with EUV."