On Dec 11, 2017 10:23, "Nick Pudar via bitcoin-dev" <bitcoin-dev@lists.linuxfoundation.org> wrote:
This topic has come up several times in recent years. While it is well intentioned, it can have devastating outcomes for people that want to save long term. If such a system were implemented, it would force people to move funds around in order to not get nullified. In that process, it introduces multiple opportunities for errors. Cold storage should be able to stay cold. I personally would be apprehensive about implementing this kind of a system.

Furthermore, if it rewards miners with funds that are expired, it creates terrible incentives. Miners in their best interest could choose to censor transactions that move funds close to their expiration time, to increase their own future rewards.

Cheers,

-- 
Pieter