As we can read it in the depreciated features list, the code has not been removed but the form JmgWorkPlanner, was not migrated cause you guess that this form isn't really used onto the 2012 AX version. We don't agree at all.
This is a very very user friendly interface !!! We need it to convince our customers to migrate under D365.
From our point of you, it'sn't a big effort for you - 99% of the functionnality is in place - so please finish the job, add the entry point and check security.
I really thank you !!!!