True, after I have seen your post and thought about it longer, having to sleep in the school would be better and much less of a "Wait no go back" thing with new players if they just go out the door like I did. Though what to do with the non-dream door if you go to it after defeating Ms. Slithers would still be up in the air.
I also feel like it could do good for introspection on the player, and give some hazy backstory for theories, though I don't know how it would go with how much variety it could have. Though it could also be a revisit of the dream eater, which would be cool.
Thanks very much for the reply Ryarod!