Well, I'm fairly certain that the derailleur hit the spokes. There was thick mud and assorted woodsy debris involved, so I'm not worried about the root cause of the derailleur getting in the spokes. I can feel some barbs as I run my fingers along the spokes. They're definitely worse off than they were before the incident. The biggest issue for me is when I'll have time to replace them.

When I do the replacement, do I need to worry about what's going on with the rim when I take them out? Like should I replace one before removing the other?