It would be good to be able to view results of Threat Explorer deletion requests or other actions, either in the UI and / or by Powershell. We can view results if we don't switch out of the window, but if we switch out, it's gone.
you folks take action from Threat Management > Explorer (Malware/ Phish or All-mail view). Once the action is taken, a related remediation is created for it and a temporary page shows up in the same view. You dont have to wait on the same page to view this remediation.
You can always go to Threat Management > Review > Action Center where you will find the same remediation you had created. On clicking on that, you will get to see a view like this:
Mail submissions tab shows the mails submitted by you and action logs show the result related to that. Double clicking on that will give you details of success and failures.