Sure. There are fanfics that explore their relationship in a way that is more about camaraderie. For example, they might write about how they strategize together to fight off zombies or deal with other threats in their world. Their relationship is complex and interesting, and many fans like to delve into it from a non - inappropriate perspective.
Daryl Dixon isn't gay in the comics. The storylines mainly revolve around his adventures and struggles in a post-apocalyptic world, not his sexual orientation.