You can follow the steps detailed below to isolate and delete all the Resource Statuses -

1.Create a Resource User Field ("Filter") >Assign a random filtering value to the selected Resources > filter them in the Resource browser.
 

2. Right-click on header > Customize Column to display Statuses and change the status to empty on one of the Resources -

3. Click on the edge of the empty cell and drag down the empty values to the rest of the Resources -