You could be the only way would be by make the npc name hidden by setting the alpha channel to 0 in the color.json (Server\resources\color.json)
Exemple:
"AgressiveNpcName": "argb(255,255,40,0)", -> "AgressiveNpcName": "argb(0,255,40,0)",
"AgressiveNpcNameBorder": "argb(255,0,0,0)", -> "AgressiveNpcNameBorder": "argb(0,0,0,0)",
"AgressiveNpcNameBackground": "argb(180,0,0,0)", -> "AgressiveNpcNameBackground": "argb(0,0,0,0)",
But that change would hide the name of every npc of that type. It would wnt to choose which specific npc name you want to hide from the npc editor you will need to wait until the engine go open source.