I'd suggest checking manga forums or dedicated Bleach fan sites. They often have detailed breakdowns and recommendations on where to pick up after a specific part. Sometimes, the author or official sources might provide cues as well.
Honestly, I don't know when the TYBW manga starts. But you could search manga databases or ask in manga enthusiast communities to get the details you need.
Some characters might be amused. For example, Ichigo might find it interesting to see how fans imagine his adventures in different ways. He could chuckle at some of the more out - there scenarios.
Rukia would probably be very critical at first. Since she is quite serious, she might nitpick the inaccuracies in the fanfiction. But she might also secretly enjoy the ones that show her in a positive light, like those highlighting her friendship with Ichigo. In the Bleach universe, characters are used to their own stories, and fanfiction would be a whole new and unexpected take on their lives. The zanpakuto spirits might also have interesting reactions if they could read, as they have their own personalities and might be offended or flattered by how they are depicted in the fanfictions.