Save you the click. MailChimp was a web agencie's internal project. It wasn't abandoned, it was just not the focus of their business. The pivoted from an agency to full time launching mailchip.
This article seems like a for-pay puff piece when it was originally published in December 2020, but the posting here and now when this company is going through a bit of negative PR is a bit suspect.
https://www.theverge.com/22300931/mailchimp-company-culture-...
https://www.theverge.com/22300931/mailchimp-company-culture-...
(via https://news.ycombinator.com/item?id=26316847)
And, not so much a "wink & nudge" as a reminder to question why any particular company on any particular topic is getting coverage at any particular time. (And an awareness than many on HN care little about the issue.)