Unito's policy concerning content deletion is that no matter what type of content is deleted on one platform, a sync will not delete it on the other platform.
For example, say you have a project synced in Wrike and JIRA, and you delete a comment in Wrike. When syncing happens, this comment will still appear in JIRA, although it was deleted in Wrike. Further syncs will not make the deleted comment reappear in Wrike (even though it appears in JIRA). To fully delete it, you would have to manually delete the comment on both platforms.
The same process holds true for tasks. To fully delete a task, you have to manually delete it on both platforms, as a sync will not automatically delete it on one platform if it was deleted on the other.
We have this policy in place for one simple reason: We care deeply about your data security. We are firmly of the opinion that if there's a mistake made on a user's end, or on our own, we don't want your data to be deleted as a result. Unito is completely safe to use for this reason, and you can experiment and try things with the knowledge that no matter what happens, your data is safe.
If you have any questions about this policy, or any of our others, feel free to contact us.