Retrieve Deleted plan
One answer
No, but if you did not created any custom view you can easily instantiate the plan. If you are using the any version 5.0.2+ you can even copy plan views between different plans instances.
Comments
How do I instantiate the plan? When a plan is deleted do the work items associated with it gets deleted?
The plan is a kind of view only! The work items are listed because they share the same iterations (planned for) and the team/category (Filled against).
To delete work items you must be a JazzAdmin and configure the delete permission! It's not a simple action!