Torres strait Islanders have these cautions: I have a cousin from there who has passed away.
Protocols can include but are not limited to:
Not using the name of a person who has passed away.
Not broadcasting the voice of a person who has passed away
Sometimes prohibition to depict the picture of the person who has passed away.
The Yolngu people in the Northern Territory have similar protocols.
It seems that in today's world, not all peoples, as you point out with the Murri people, adhere strictly to these protocols. It seems to be a personal choice. So perhaps rather than "making it a rule" you should allow the option of using another name by which they are recognised. eh?
Normally you have to obtain permission from the Elders to use the Indigenous name of a deceased person (out of respect), as in the case of famous singers, for instance.