Well you can't say Valve only cares about Team Fortress 2. Train (or de_train), a classic map from Counter-Strike 1.6 times, just got a facelift and a redesigned layout for Counter-Strike: Global Offensive.
At first the new design with all the trains and cargo containers might look complicated for a fast-paced competitive map, but the old design was actually even more complex. That's one of the reasons for the new look:
We've rebuilt the map from the ground up in order to improve both the visual appearance and competitive gameplay balance of this iconic location.
Our primary goals were to improve the gameplay balance of the map while simultaneously upgrading the overall visual experience. This meant making more intuitive layout changes, then re-interpreting large and small-scale environment elements to improve judgement of space and distance.
Below is the official video from Valve with all the changes they have made during development, shown in a timelapse. It's pretty straightforward. Otherwise, the map might look a bit more cartoony compared to the original. But the industrial theme rather reminds me of Half-Life 2 and not Team Fortress.
Now we all have to do is find Half-Life 3 clues in it.
Here's a quick first-person walkthrough from YouTuber rechyyy: