Game of stake incentive need to be more specific about what's the valid validator uptime

As we all know that validators which were created from genesis txs are of course valid validators. But what if some validators lost their priv_validator.json file but have secret words at hand. Because there’s no way to find the priv_validator.json file. It’s on the one hand. On the other hand, if they want to recreate validator just from original account, they have to wait several days to complete the unbond operation. Considering the high inflation rate, the cost is too high. Could they transfer the tokens to some other account. And with that account, validator can be created immediately. But, I’m not sure whether this validator uptime will be calculated when distributing incentive. Could someone make a clarification about it.