I understood most of what he said:
Valve's inventor left the company in January 2016, did you forget that? We can't expect the next Half-Life game because he is old, and he's also ill, that's why we can't expect its release. Please pay some respect to Valve. I think there are no newer releases than Half-Life 2. Please use another engine like Unreal Engine 4.9 / 5.0 or other so we can continue with other engines. But please don't revert to the old Half-Life (GoldSRC) engine.
Do you know who remade Half-Life 2? For example: City 17 to Unreal Engine 4.9 / 5.0 because it looks very realistic, along with the grass on the ground like in real life. That is why Valve Software can not get a chance t develop a good and a stable engine. I surely think Half-Life 3 has stopped development. No, Half-Life 3 won't come out. We'll only have Half-Life 2 and its Source engine.
Source 2 looks like Dragon World or Age of Empire 3 with a rotating camera view. Source 2 is not built for single player. Tiled map versions only look like 2D tiled maps but with a rotating camera view.
Huff... puff... can't... I'm too tired of translating. I think I should become his "Understand-inator 4000", who makes everything understandable.