Using Edit->Undo or Ctrl+Z has no affect after breaking using Alt+Click to break the connection of transition nodes. In the My Blueprint tab, extend Graphs->AnimGraph
No - Same behavior exists in 4.13.2 and 4.14.0
Ctrl+Z has no affect and Edit->Undo History only shows the node as having been clicked on, it does not list the connection being broken as an action that can be undone.
Using Ctrl+Z or Edit->Undo will reestablish the connection between the nodes.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-39068 in the post.