Currently, the wandering trader elephant variant is programmed to eventually disappear much like the wandering trader and trader llama (unless the llama is tamed). However, unlike the llamas, the elephant can still disappear even if it is tamed, which is a shame because it would be so cool to have the trader elephants around. Is there a way to make it so they won't despawn when tamed like trader llamas?

They do not disappear after being tamed. This is a bug though.