Offline gameplay confirmed, so chill

[Lofren]

http://www.playnation.de/spiele-news/anno-2205/nach-uplay-aktivierung-komplett-offline-spielbar-id61279.html

Translation

Anno 2205 can be be played entirely offline - after you activate it once on Uplay. Apparently, Ubisoft has learnt a lesson from the issues of the last couple of Anno games and does not want to put a strain on the community by enforcing overly strict DRM. However, if you do play it online, you will be able to access additional features.
Anno 2205's creative director pledges that the game can be played entirely without an internet connection - after you activate it once on Uplay. Although that might sound normal to players who did not play Anno before, fans of the city-building strategy game cited the DRM as one the most severe issues of the series in recent years.
In Anno 2070, your game experience was limited when you were not permanently connected to the internet. This often led to players' frustration, as the game frequently did not work properly in the event of internet outage or slow connection. The servers did not always function properly as well, so in that case, Anno 2070 became nearly unusable.
With Anno 2205, this is going to change. "You can play the game entirely without an internet connection", Dirk Riegert, Anno 2205's creative director states, when interviewed by the German magazine "GameStar". "Production of goods, trade and population development do not run remotely on any servers, but solely on your PC. And only when the game is running".