The GMO gene in Golden Rice is patented. It’s just licensed for use for free in developing countries on small hold farms. A monoculture of golden rice would be less diverse than the current wide range of heritage rice varieties, and there could be over reliance on it which could case issues if there was a blight. Theres some concern that spread of the genes could catch unaware farmers with legal issues, but it’s harder for rice genes to spread than most other crops, as they’re usually self-pollinating. The risks dont seem to outweigh the benefits in this case, but it is more complex than it appears on the surface level. Greenpeace doesn’t seem to be able to use scientific research to back its claims here, and is instead just staying true to it’s anti-GMO message.