Say you are attempting to delete a tweet you made: you click on the delete button, and you want to see that your tweet is in the process of being deleted, but not really deleted yet (as the platform goes and updates all the retweet references and such)?

Really? What value do you as a user get from knowing the details of this transitory state? Do you also want to see a progress bar of how many references have been updated, what's the progress of evicting the tweet from search indexes, etc? What's wrong with all this appearing instantaneous and actual delete happening in the background over 5 minutes or 5 hours?

It seems you are in favour of this approach, just don't want to call it "soft delete" (since it may be followed by a hard out-of-band delete).