He said the game's setting isn't limited to the asylum at all. So it's possible. Although, yes, seeing as how the monsters' origin isn't grounded in reality, the protagonist is unlikely to end up in some kind of bio lab which he has to blow up.
We'll see something like the 2001: Space Odyssey ending. Or I guess we could if the game was some low budget indie title. But this one has to sell, so yeah - the explosion and escape via helicopter is inevitable.