Your statement that merges were done without notifying the managers is incorrect. If you look at changes log for each of the profiles that were merged away, there is a proposed merge that was done months before the merge was completed. Possibly the proposed merge email was missed, list, or forgotten about, but a proposed merge was done.
You mentioned Wills that mention the person. Were those included in the profile for Ann? If not, then there was information missing in the profile that could have been used, but without it, there is no knowledge.
When there are multiple people with same or similar names and limited information on profiles to distinguish them, incorrect merges can be done. Soneone would need to create a new profile to correct things, since merges cannot be reversed. Sometimes people compkete merges without checking information on profiles or comments. Accidents happen and profiles would need to be recreated.