I would say Silent Hill is not really a stealth survival horror game and turning off the flashlight has nothing to do with it. I've beaten 1-3 so I have played them.
In a stealth game, you have to sneak around and if you are discovered you can be killed easily or overwhelmed by enemies. This is only true in a few examples of horror games like Siren and maybe Call of Cthulhu: DCOE for certain parts of the game.
In Silent Hill, if you are discovered you can easily escape enemies with little consequence or just open a door to the next room. It's even harder to escape enemies in the first RE game compared to Silent Hill.
I would say then even the first Thief game is more of a stealth survival horror since it has undead/zombies and it is a pure stealth game. The atmosphere is more frightening than many modern survival horror games these days.