The workaround for this is as follows:
1). Create a Document Property and attach the IronPython script to execute on Document Property change.
2). In the "Open Analysis from Library" job , in configuration block set the document property created in the previous step to any value different than the current value saved in Step 1. For example:
documentProperty=Value1;
3). This will now trigger the IronPython script to execute upon opening of the analysis using Automation services.