Nope. 'All of Us Are Dead' is purely fictional. The plot, characters, and situations are made up to provide an exciting and captivating viewing experience, not to represent actual happenings.
The phrase "Pan it" originated from Meng Hetang and Zhou Jiuliang's crosstalk,"Wen Wan." The original words were: "Dry, Ma Ma Lai, not round at all, Pan it!" It meant that if you didn't like something, you could make it round. Later, this term was widely spread on the Internet and became a popular term.
In the TV series "Celebrating the Years," the word "plate it" was also mentioned many times and became a meme of the show. In the play, when Fan Xian (played by Zhang Ruoyun) had a conflict with Lin Gong (played by Liu Runnan), he once said the phrase "stick to him." Later, this phrase quickly became popular on the Internet and became a popular saying.
In short, the word "plate it" did not have any special meaning in "Celebrating Years". It was just a popular use.
My answer was not accurate enough. According to my knowledge of online literature, there is no description or mention of a 70-year-old woman named "Kang Kang". You might have remembered the name or the plot wrongly. If you can provide more information, I will try my best to answer your questions.