So summing up some of the other comments, it sounds like the main use case is to either leave it with the existing subtle differences, or take advantage of the css class to either tastefully or ... not so tastefully ... highlight the admin posts so they're much easier to spot.

When kaberett's changes to the support board to highlight the different types of comment there with dashes as well as changes to line color came into effect, I was surprised and very pleased with how much cognitive overhead it removed for me. I hadn't thought I was spending so much of my attention on telling the comment types apart by color, and yet the removal freed up so much attention.