Yup, I felt it was a nice addition. I like that Naoto has a feeling Yu knows more then he's letting on and possibly sabotaged the investigation for a reason. Though she says nothing because she simply can't prove but you can't shake a gut feeling and with Naoto, alot of her gut feelings end up being true.
Let me emphasize what I didn't like about the episode. I didn't like how "in-your-face" it was about it all. Like, why did Yu confront him inside the TV? In the original he'd simply walk up to him on the station and tell him he knew everything and was willing to help him. It felt so much more intense, when it was the real world, and of course Adachi's reaction and the writing was excellent. Why did Adachi have to randomly show up everywhere, almost as if the director of the episode would sit behind you, poking you constantly, while reminding you "Look, it's that guy whom is the murderer you chose to help, you may now proceed to feel bad". Heck, at the end, it feels like Adachi is being directed by some unseen force going "Okay, listen, as soon as the train gets close, you'll walk over it, very casually and cool. You got it?". Adachi is literally being summoned everywhere by plot convenience. I think it felt more intense in the game, where it's undetermined where he's standing, as he's covered by fog, then it cuts to Yu getting a mysterious message on his phone, as he clings to his it in anguish; The game then ends with a cut of the train disappearing into the tunnel. It was great.
Looking aside of these issues. I liked it well enough.