I think the impulse to promote all meetups was a good idea but now adding to much noise to the "PROMOTED" feed. Of the 10 "PROMOTED" feeds 8 are adverts for meetups.
I propose adding Meetups to the navigation bar and only adding them to "PROMOTED" when they are especially significant; for example have a special speaker and might draw attention from people who are out of town.
The problem is that I'd want a high probability of people noticing meet-ups they want to attend. I suggest meet-ups as both a tab on the top navigation bar and as an upcoming meet-ups list on the right-hand margin. It sounds redundant, but that seems to be livable for comments.