It means new Bitcoin can be created that loads more bitcoins to total supply that is initially set at 21M.

Do you think about who will be new owners of reintroduced bitcoins as replacements for inactive owners?

What do inactive owners think if such reintroduction of bitcoins is made?
They likely are dead people, lost their private keys or they just inactively with their bitcoins but still have private key access.

Your proposal is not logic in thinking and it's controversy if it is activated on the network.