"Nothing good" is the answer to that title question. It's kind of insane that someone went through all of the trouble of picking up a ton of items just to drop them all at Sanctuary to see what happens.
And apparently the only thing that did happen was an extreme drop in framerate and a giant mess that, I hope, he cleaned up later. At least Dogmeat seems pretty happy, right?
Over on reddit, he outlined the steps he took to get all this junk and apparel and weapons in his inventory. Part of me wants to believe that he just picked up every item in the game and dropped it. If you want to read his full explanation you can do so here.
But he still doesn't answer one very important question: