Well, currently, the sidebar displays "recent posts" and "recent discussion." If it also displayed "recent meetups" separately, people would continue to get notice of meetups without them cluttering the discussion section.
Concerns about programming effort and fragmenting the site still apply.
It already displays "nearest meetups"? (Maybe you need to have your location set in order to see that section.)
Six out of the last 10 posts are about single meetups. And I care about none of them.
I will look into whipping together some kind of bot that periodically posts threads like the open thread or a meetup thread. Voice your opinion in the comments if you do not want me to do that.
That is all.