And finally just because some coins are burnt (provably lost) that doesn't mean we have to create a fork to "un-burn" them and enter them into circulation. Satoshi discussed this once if I'm not mistaken, unless a ridiculous number of coins are provably burnt (something like 18 million BTC send to OP_RETURN for example) and the lack of circulating supply is felt, there is no reason for any kind of action.
Altcoins with their premined, minted coins or tokens have many burn events and they love to compromise their premined/ minted amount. They get rich from beginning (with premined, minted amount) and get richer with burn events. Events to burn are for altcoins, not for bitcoin. The event only causes unreal feelings on scarcity of those altcoins but it is feasible to use and make altcoin investors mad with their decisions.
I'm not suggesting that we burn bitcoin on purpose, I'm talking about the case where we can know without a shadow of a doubt that the coins are indeed burnt not just guess that certain amount of coins are burnt just because they haven't moved in some time like what OP suggested.
Besides what altcoins do is not even actually affecting the reality of their supply because they can also print as many as they want later on if the price pumped and stayed pumped.