And how is SE meant to track this, for them all they see is "subscription ends" they see no "why". Do you want them to look at death certificate's? Or what ever proof can be given.

If no proof is required players will make an alt, end its subscription and demand a grave/monument etc. We life in a world in which players abuse all things to get benefits or superficial benefits sadly.

I'm not sure this would translate well into the game even though the idea would be nice and those players that were lost would love it and deserve it, but would you chase down their families for a death certificate? And if no proof is required players will abuse it.