I stopped checking the forum topic regularly and it turns out the devs have most likely found a solution to the now two-month old problem.
Source
According to CS representative Natryndon:The development team members working on this issue believe they have now found a solution and are hoping to implement this in patch 6.1. If everything goes according to plan, the fix should merge your wiped data/artifacts etc. with your current information. If your skill level was higher before the incident, you will be boosted back up to your previous level. We will be monitoring the situation closely once patch 6.1 launches and will continue to use this thread to provide updates.
Hopefully, the fix will be deployed on the 6.1 PTR soon for testing.