Theory: Milchick is actually a milkshake
Now I know this might sound crazy but hear me out. What if milchick being called milkshake wasn't actually a joke, but instead was the show telling us both his backstory and how the show will end? Think about it:
•Milkshakes are cold, and milchick is shown to be a very cold person emotionally
•MDR has had melon bars and egg bars, but never a milkshake bar. This could be because milchick does not want to be eaten by Mark and the rest of the innies
•During the defiant jazz sequence, milchick was shaking all over the place while the rest of MDR just moved slightly. When I looked at milchick I thought "how is he so good at that" well maybe it's because being a milkshake would've given him lots of experience with shaking. This could also explain why Dylan got so angry as he may hate milkshakes which would make him irrationally angry at milchick, causing him to attack
•The lumon building is located in a very cold area, with snow everywhere. This is not due to weather, but actually because milkshakes must be kept at a cold temperature or they will melt. Milchick needs to stay in that area or he will melt like the milkshake man he is
•I like milkshakes and I also like Mr Milchick he's pretty cool
I think the proof speaks for itself. But what does this mean for the show? Well here's what I think will happen: it will be revealed that Lumon isn't cloning or trying to achieve immortality, but is actually turning people into milkshakes. Mr milchick was one of the first milkshakes, so he would be given a job of high importance like management. This could also explain ms huang, as she is a child and thus would be too young to turn into a milkshake, so Mr Milchick would have to watch over her to make sure she will be ready when she reaches milkshake age. That's why she's the new supervisor, so milchick can keep an eye on her. But why would lumon want to turn people into milkshakes? It's simple, Keir was a big milkshake fan and when he was a small boy someone said to him "if you love milkshakes so much then why don't you just become one?" This set him on his life path, turning everyone into milkshakes. I think the final scene of the show will be Mark finding the original Kier. He goes "where is my wife?" but kier just turns around in his chair and it's revealed that he is a milkshake, the first milkshake. He then presses a button and a second chair turns around, revealing Gemma is now also a milkshake. Mark will drop to his knees in despair and the show will end. Bravo Dan Erickson you've done it again