The poster of the gang in the acorn is a homage to the poster of Monty Python and the Holy Grail (1975).
In this sequel, the nut shop is called, "Nibbler's Nuts". In The Nut Job (2014) the shop is called "Maury's Nuts". It's possible that the last name of Lana, King's girlfriend, is Nibbler.
This will be Will Arnett's second animated film in 2017. He is also in The Lego Batman Movie (2017) six months prior.
Mr. Feng, voiced by Jackie Chan, is shown to have a one-inch punch attack. Coincidentally, the one-inch punch is commonly attributed to Bruce Lee, whom Jackie Chan had been a stuntman on two of his films (The Chinese Connection (1972) and Enter the Dragon (1973), specifically).
Tom Kenny's second animated sequel despite not saying a single line in the entire film.
Maya Rudolph's 2nd animated film, just 2 weeks after The Emoji Movie (2017) released.