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 parent drafts and child drafts. But its subtasks will be not unlinked.
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At any time once a sub task is deleted directly from its parent draft, it will be permanently removed. You can not find it the deleted subtasks in Deleted draft page. Subtask can only exists under its parent draft.
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