ReDistrubute all coins that were not moved since 25 years would be a way to have tail emissions while keeping the 21M  limit .. while you make sure lost coins get reused and old addresses get updated (reducing technical debt and level up security). 

 All it would require is to move coins once every generation (to a new address) to protect them from redistribution thru mining. I think thats a fair deal if communicated early. 

 And sorry .. it should be every 21 years, not every 25 years of cause.