I think the Hive wants to keep the death messages as simple as possible so they are easy to read and understand at a glance. I also don’t feel the need for this due to the fact that assists don’t reward XP so this information is not really necessary on the death message.
This is also a duplicate and in the wrong section of the forums, you can find the original post here: https://forum.playhive.com/t/kill-assist-system-in-pvp-games