According to NFL Network's Tom Pelissero, Robinson did so to signal his level of frustration over the team failing to meet his demands on a long-term extension:
Tom Pelissero @TomPelissero
#Bears WR Allen Robinson has removed references to the team from his social media -- a reflection of his frustration over the state of talks on a new contract, sources say. No trade request as of now, and Chicago has a history of getting extensions done. Stay tuned. @nflnetwork https://t.co/JKbhKEqYoX
While Pelissero reported Robinson had not requested a trade, Brad Biggs of the Chicago Tribune reported the wideout has asked about a trade.
Robinson's agent later denied those rumors:
Robinson is earning a $10.9 million base salary in 2020 before he becomes a free agent this offseason.
The 27-year-old is coming off a solid 2019 season in which he caught 98 passes for 1,147 yards and seven touchdowns. His numbers likely would've been even better if not for Mitchell Trubisky's erratic performances.
Since signing his three-year deal with the Bears in March 2018, Robinson has watched a number of his peers cash in with new contracts.
DeAndre Hopkins just got a two-year, $54.5 million extension from the Arizona Cardinals, while Keenan Allen put pen to paper on a four-year extension worth $80.1 million. Adam Thielen (four years, $64.2 million) and Amari Cooper (five years, $100 million) are among the others to secure a healthy raise.
Few would classify Robinson as being among the league's best wideouts, but he could plausibly argue his circumstances have done him no favors. He must wonder what he did to anger the football gods by going from Blake Bortles with the Jacksonville Jaguars to Trubisky.
Robinson is clearly the Bears' best receiver, so you'd expect them to make every effort to keep him.
The fact he's adopting a passive-aggressive approach to convey his exasperation would seemingly point to a significant stalemate between the two sides.