There are basically two reasons for the film to be released again, the first is for the benefit, and the second is for the reputation. For the benefit, the copyright party will choose to remake and replay many movies with audience base. The cost of remake is only a few million, but it is unlikely to get more box office income. For example, Titanic, the ashes of time and a Chinese Odyssey should all fall into this category.
Some movies are replayed not for those humble interests, but to commemorate the birth of good movies and let everyone relive their feelings when watching movies. I believe that the film Red Sorghum is to commemorate the 30th anniversary of the film's birth, and also to give the film creators an opportunity to review history. It can be regarded as a love letter from the copyright owner to Zhang Yimou, Jiang Wen and Gong Li.