Correct But Misleading Notation
On the Merge Analysis screen, this is shown:
The Undo Merge button is going to be inactive the vast majority of the time because usually at least some editing is done after a merge. This is going to be deceiving for some users because it is going to make them think nothing can be done to reverse the effects of the merge other than to do more editing to the profile by deleting relationships and removing information. In particular new users who do not know that they can still go to the deleted person's profile to restore the profile will likely be prone to make the results of an incorrect merge worse by removing all trace that the delete person ever existed and removing all the correct relationships of spouses and children to that deleted person.
The text under the information icon does not help matters because it just states "Select Undo Merge to restore both persons to their state before the merge. Undo Merge is disabled when changes have been made after the merge" which reinforces the notion that the deleted person is gone forever.
The Merge Analysis screen needs another button:
with suitable text under the information icon to explain what restoring a profile does and does not do. This will remind all users, new and experienced, that incorrect merges can be reversed even after editing in order to not completely lose the deleted person and that person's relationships from Family Tree.