I mean, Kleiner saying “I had expected more warning!” is a sort of mixed surprise. If he’s been gone for 20+ years, the natural reaction I might expect is “What…? That’s impossible! We all thought you were dead! Or lost in Xen forever!” Heck, even Kleiner’s reaction to the “slow teleport” you and Alyx take late in the game is much grander. “I had…given up hope of ever seeing you again!!”
They don’t question it because all kinds of weird interdimensional shit is going down. But they absolutely react with surprise when you first show up.
I mean, Kleiner saying “I had expected more warning!” is a sort of mixed surprise. If he’s been gone for 20+ years, the natural reaction I might expect is “What…? That’s impossible! We all thought you were dead! Or lost in Xen forever!” Heck, even Kleiner’s reaction to the “slow teleport” you and Alyx take late in the game is much grander. “I had…given up hope of ever seeing you again!!”