Hello - I'm the original organiser mentioned in the article. I have a bit more information that might add some context.
I created the meet-up page years ago and it had been left with my name as the 'owner' of the group, although the organiser role had moved to other people.
Recently my meetup account was automatically deleted by meetup. The reason given was an invalid e-mail address - this is not the case, the e-mail address for my account was valid and I was regularly receiving e-mails from them (mainly marketing e-mails). There does not seem to be a missed payment, although I could be mistaken. I did receive one e-mail telling me that they were unable to send me e-mails, but I foolishly thought it was another marketing e-mail and didn't read it at the time.
At this point, the organisers of the group (set up with organiser accounts on the site) were not informed - other wise they would have been able to sort this before anything happened. Instead, an invitation to take over the group was sent to all 700 members, at which point someone seemed to take over it in order to promote their own unrelated veganism and anarcho-capitalism events and associated YouTube channel. The channel's name is "Karma Krack" for anyone interested and it is hosted by one of the two people who took over the group's page.
This incident has been interesting. It's shown us that when taking over a group it is very important to be thorough and get control of everything - I forgot to give up ownership of the meetup page, which was a big mistake on my part.
I also think the meetup procedure is flawed, although I am clearly biased on that account. In any case, this is my opinion on the procedure we experienced;
Meetup should really offer ownership of the group to the people listed as running the group before offering it to everybody. This would avoid situations like this where people take over groups for their own gain. Also, it's a bit worrying that meetup is deleting accounts for having invalid e-mails when the e-mail address is actually valid.
It's not a massive problem, but I understand it was a very annoying few days for the current organisers of the group. I hope this adds a bit of context for anyone who has read this.