const314

If your events are well defined, you should be able to understand what happened by looking only on the event names. So, SetKeyValue is not good here: "what key? what does it mean?". CustomerEmailSet or CustomerEmailChanged clearly describes what happened with the customer.

We don't delete events, just replace sensitive info in events with the specific string marker (by direct update in DB) and then update projections. In this case, the system remains consistent because all the related aggregates and events are still there. You can safely rebuild all the projections without issues and see these string markers instead of deleted info.