The Berlin mention is a reference to the Brandenburg airport which has been under construction since 2006 and was scheduled to be completed in 2012. They are now hoping to open in 2020 or 2021.
Yes as I was checking the spelling of Tegel I came across the Brandenburg airport information and linked to it above. It makes Terminal 5 look fast and flawless by comparison!
http://madridjournals.com/2017/12/14/berlins-money-guzzling-...