Your deleted drafts will be still saved for 60 days in the Deleted draft page. Once a draft is deleted, it will unlinked with any of its child drafts. But its subtasks will be not unlinked.
Deleted drafts
Delete Subtask
At any time once a sub task is deleted directly from its parent draft, it will be permanently removed. You can not find the deleted subtasks in Deleted draft page. Subtask can only exists under its parent draft.
