We set all links to old Symposium posts to redirect to the corresponding URL on fanhackers.transformativeworks.org, the new home of the old WordPress site. This was working fine when we launched three weeks ago, but the redirects don’t seem to be working now. Apologies for the inconvenience! I’ve alerted the people who can hopefully fix this soon. Thanks a lot for letting us know.
ETA: The redirects seem to be working again now, please poke again if something else seems out of order.