Portal 2 Closing Scene Does Not Fit With The Rest of The Story [closed]

Solution 1:

I'd say it's a case of moving architecture. We see in Portal 2 how entire rooms can be shuffled around the underground without much of a hassle. When GLaDOS started cleaning the place up she probably decided it'd be safer in some way to have her room not directly under the surface. Wheatley probably put it back when he was in control because he's a genius that way; it was then moved back down afterwards.

Solution 2:

When you are woken up again by the robots you are in the chamber where the first core transplant takes place. I assume it is because this one has not been destroyed. This chamber is obviously further down.

Also maybe the turrets wanted you to go though their chamber so that they can sing to you.