While this topic has been brought up before, it is important to bring it up repeatedly. Lightforged Draenei are long overdue for a unique paladin mount that is specific to them. Currently, the mount they are given is shared with Draenei paladin, the Great Exarch Elekk. Every race except for the lightforged has its own unique paladin mount that fits its theme. Dwarfs and Dark Iron Dwarf paladins use the same model mount, but each mount is re-skinned to fit the theme of the race. Dark Iron Dwarfs are closely related to fire, and their paladin mount reflects this. Lightforged Draenei are infused with the light, and so would their paladin mount be infused with the light and use gold/yellow crystal schemes.
The solution to this problem would be to either re-skin the Draenei Paladin Mount or create a new unique mount for lightforged Draenei, such as a lightforged Talbuk/Ruinstrider mount. Hopefully, this issue will be fixed soon to finally allow Lightforged Draenei paladins to use their own unique mount like all the other paladin races.