Wow this looks amazing.

I don't exactly understand, how the texturing works:

"Buildings were textured using a procedural system which utilized a shader that could overlay 2 UV regions from a single atlas. Each UV tile could be spread apart with an offset to get the proper spacing between windows and other detail elements"

This sounds like magic to me.

I think I get it, it's pretty smart. So you have a texture atlas - a big texture with many small textures packed into it. Each small texture occupies a rectangular UV region in the big atlas, and when you are looking up texture coordinates x,y of the small texture, you remap them from (0,0)-(1,1) to the coordinates of the region in the atlas. This lets you avoid having a ton of small textures and instead use one big texture, only changing the UV region before drawing each model.

What he's talking about is a more advanced version that lets you do multitexturing from a single atlas - use two small textures and blend between them, with each having different tiling settings to make everything line up. The way I imagine it works is like so:

You're trying to draw a concrete cube with windows on each side, spaced 1m apart vertically. You load up a concrete texture and a window texture in the atlas. You set up the concrete texture to tile continuously. You set up the window texture to repeat with an offset that lines it up with the building's UV coordinates such that the windows appear horizontally and vertically where they should. The shader then chooses the window texture if the UV coordinates fall within the window tile, or the concrete texture otherwise. Depending on how complicated you make the tiling, you can get a lot of effects this way.

P.S. Look at the second link's first screenshot. The building that's second from the bottom, facing towards us. The windows are all spaced equally.

I'm pretty sure that the Sims franchise, which used to be a Maxis product, has been and still is incredibly profitable for EA.

Probably more so than SimCity ever could have been, just due to the size of the target audience[1]. Of course, why not do both?

[1] And maybe it's easier to sell content packs for The Sims, though Paradox sure seems to be trying to do the same for C:S.