Do you know if it is possible to implement a feature here where a user could upload their data from another platform (specifically Facebook) and get automatic "memories"-style posts (which they can choose whether or not to post) here on the anniversary dates of the old posts?

I think it would be a big selling point for people moving away from Meta to have such a feature. A lot of us spent the better part of 15 to 20 years there and don't want to lose everything.