Mutate from non-GM to GM?
The process of genetically modifying crops is performed in a lab. Genes would not leak into planted organic crops from compost any more than they would move from decomposing soil nematodes, earthworms, or manure. So no, organic plants would not be genetically modified. However, the labeling of a crop as "organic" is not always standardized, so it could be a cause of concern for some people who do not understand the process.