No it's a prequel. So you get more world building but no resolution.

IDK what the other person was on, but it's not a separate story with separate characters in a different part of the world. It still takes place in Eastern Europe, and everyone you expect to be in a HL2 is there except Gordon.

If you don't have a VR headset yet, they're way cheaper now than they used to be. So you should definitely consider getting one for this game. Hell VR is worth it for the porn alone.