Uncle here refers to Rui Chen, Chairman and CEO of Bi Li Bi Li Company. The reason why Chen Rui is called uncle is related to a Japanese same-sex movie.
The first hero's "Park Soo" looks like Xu Yi, the founder of Bili Bili, and the first hero is abused by the second man's "uncle abuse". This secondary relationship is reminiscent of the real world, when Xu Yi was snatched by Rui Chen from the webmaster of the mile mile.
Thus, in the mouth of the netizens, Xu Yi became Park Xiu and Rui Chen became an uncle.
The uncle in the film has a line called "Uncle, I'm really angry", so BUs always quotes this line when poking fun at Chen Rui. At first, it was ironic to call Rui Chen or Bili Bili Uncle alone, but after everyone called him that, it almost became a neutral word.