Almost all forums which have soft delete don't have approved/unapproved status. I think this is the main reason why the soft delete exists. We'll take this feature under consideration but I can't promises anything at this moment. 

I don't see any different between the soft deleted post and unapproved.

Yep, do not want to see such posts anywhere near a moderation queue. A CSS hack on the unapproved list would also apply to posts that do belong in the moderation queue so that would not work. Soft delete has been part of basic forum structure since forever....

Edit: Additional info - the permissions for such posts is generally they are only viewable by Admin and/or moderators. Such posts are NOT removed from the database. Such posts are scrubbed out of the sitemap xml unless they are restored/undeleted again. 

Screenshot of what it usually looks like in a topic to an Admin.

Sorry for late response,

I don't see any different between the soft deleted post and unapproved. If you don't want to see the orange circle in dashboard menu, we can find some CSS solution.

Hide post should do just that, hide the post from everybody and search bots except mods and admins. Perhaps also add an indicator on the post that tells the mods/admins that it is a hidden post. Similar to "soft delete" on other forum platforms.