I don't know if it is said already in a post here or on the Kalypso forum,
if so I would be thankful if you can post a link to it. ...
I'm sorry, but I can not recall it. Perhaps you are thinking of one on the Kalypso German language board.
Well from now on it seems that T3 will base on 2nd World countries.
That may be so based on the look of the screenies so far. If so, it is probably a mistake if any verisimilitude is intended at all. You personally probably know the Warsaw Pact communications tower which is the T3 version of a TV station. It is of course unknown in the Western Hemisphere, but the game can't be changed at this point of development.
I think your most important question is whether there will be a change in the highly detailed visuals to correspond with the historical development of technology over the eighty years or so of the typical game.
I opine that is highly doubtful. Even though Haemimont has dubbed the editor "the timeline editor", I don't think that means they have developed a timeline guide for the art work; nor the means of changing the background art as time progresses -- at least in the sense you have in mind. Certainly the vegetation will grow as it did in T1, but the style of street lights will not change.
We may be pleasantly surprised as the infrastructure changes as time passes --- and El Presidente's avatar ages (what happens if he/she starts old?) --- but I wouldn't bet on it.
We'll just play the game that's dealt to us -- suspending lots of belief.