This makes a lot of sense... and not merely because WeWork has raise $10 billion (most of it this year). Both businesses are based on community. One is at random locations and the other operates community spaces. So where do you think Meetup events are going to be hosted now? Yep, WeWork where the offices usually clear out after hours. WeWork can also encourage/assist its members to be community leaders and give them resources to found Meetups in their areas of expertise.
What's a great way for a company that provides offices and work space for small businesses and consultants to get market intelligence in 180 countries? The data from Meetup. Data often is the real value in businesses and the data about individuals, their interests and how active they are in their communities is what WeWork acquired today.
WeWork's official announcement: https://www.wework.com/blog/posts/wework-x-meetup