It was a limitation in vanilla, troll feet had 2 seperate toes, tauren had hooves and other races had just foot with toes painted on the texture so you coul just replace a texture for a boot or a shoe but for trolls it didn’t work.
With WoD models characters have 2 foot variants, one with modeled spererate toes and one without for boots and shoes. But at this point it was established that trolls don’t cover their feet. Still some armors with custom 3 boots had some elements that partialy cover the foot. The example in the picture clearly shows it. It wasn’t full boot, most of the foot was uncovered only heel and toes were covered by additional pieces. And that looks much better.
Report it, report it that you want it to be changed back. Maybe they will.