The box's name is Gruffle. And it hates Duffers, so it has gone far, far away. And now Waldo is out in the open, probably stuck with MF (wherever she has been).
That is a significant point at the end of a very significant peninsula which has a very significant harbor named Flumpkin. How do walls talk without lips? Either they have learned to talk without them, or they (and Fred and Gruffle) have lips. Or we're just hallucinating it all, but that, of course, is not a possibility. Duffers never hallucinate. They just see things, like the chocolate-coated peppermint ships coming into Flumpkin Harbor.
Contrary to popular belief, Walls are not in fact possessed of lips. Rather, they induce modulated atmospheric vibrations (known to the vulgar as "sound") by achieving the motion of their internal pleisiophastic shift-warping fridulators against their interior surfaces. (These fridulators are rarely found in other places - in fact, the only known occurence of them outside of walls is in the Mod Fridge.) How Walls first developed ability, so similar in effect to the human function of speech that the two have often been confused, is unkown. It is speculated that Walls first used this ability as a survival technique - were they unable to release their internal pressure by this means it is likely that they would dissolve into high-pressure emanations of Cheese Whiz. However, such researches are still very much in the experimental stage and any statements made concerning the field should be taken with a very large and salty grain of salt.
Considering that Oly seems to have deserted Dufferland again, I suggest that he may have been motivated to leave by either guilt or fear. What if walls do have lips, and he was attempting to deceive us? If so, what were his motivations? What is currently being hidden by his pink beard? I, therefore, think it safer to continue holding that walls are, in fact, possessed of lips.
Who can truly understand the banana? This is the cause of the Lonely Banana's woes, but it is also a banana's glory, for the mystery of a banana is a thing unmatched through all the ages.
A friend of mine had two bananas. She decided to draw happy, puppy-love-like faces on them. They were lying side by side, happy as can be. She took a photo of them, posted it on facebook, and declared "I'll have one for my evening snack." My roommate cried, "but the poor lonely banana!"
(And no, I hadn't told her of the Lonely Banana. She just knows that I kept insisting on decorating the room with bananas. )