Font Awesome Icons
We have upgraded to Font Awesome 5 for our site icons along with the update to Bootstrap 5. Although you won’t need to update how you reference these icons in your HTML, you can update your icon classes to FA5 if you want.
Font Awesome Documentation: Basic Use
Because this is a result of moving from Bootstrap 4 to 5, if you make this change before August 3, it is recommended that you avoid publishing the page before August 3.