So far, we assumed that blocked users should be allowed to cancel their registration for an event, if they want to (though they wouldn't be able to register again).
There's a TODO in the code about this assumption, and it's been there for several months now, but I personally forgot to create a task about it, so here it is. I think it'd be great it this could be figured out soon.
DECISION:
- for V1, we can go with the current assumption that blocked users should be able to cancel their registration for an event. for v2, we can explore how to improve this experience.