20 years don't know, but I feel today most posts should be more ephemeral, why keep a post of your lunch of a random day 4 years ago?
For posterity and to be studied by future historians and ai
Yes it's very possible, even to then "talk to the dead" using AI. Don't know if personally would want that though. But yes it can be useful in many situations, like today being able to see Satoshi comments on the forums.