As this is quite interesting topic I dug some more and btw people on Reddit are much more active in that direction than the ones here.

Again I love the game, but what is true is true and what is wrong is wrong, so here is what I found:

Community Update #19: Mechs and the City

Just a few quotes from it:

"This weekend, we unveiled the city of Baldur's Gate for the very first time, with a glimpse behind its walls and around its familiar labyrinthine streets. It's been about 20 years since we last had a pint in the Elfsong Tavern or crawled through the sewers beneath the city streets and, as you might have spotted during the PC Gaming Show, many of these locations are back, and many news ones are waiting to be discovered for the first time - giving you a chance to explore the menacing roads of the Outer City, the opulent estates of the Upper City, and the dark alleys and pubs of the Lower City."

and...

"What's come out of that decision is something were very proud of. The districts of Baldur's Gate are now three seamless open worlds."

No offence, but I think we should clearly have a DLC.