This was an issue with a permalink structure on the site. WP Meetup seems to lack any capability to update links and doesn’t clean its data when uninstalled. So, as a quick solution, I dropped the posts from wp_posts, dropped the wp_meetup_events table, reinstalled WP Meetup, and reimported events to put them on the new permalink structure. However, WP Meetup 2.1.11 ignores the site’s specified permalink structure and generates events using /events/%postname% instead.
Incidentally, this explains meetup.com events not appearing in the post editor; they’re inserted into wp_posts with post_type = events rather than post_type = post. Events are also created with post_status = publish, comment_status = open, and ping_status = open.
