The tweet definitely leaves a lot out. My initial impression was, "that sounds reasonable." I got insurance retroactive to my hire date when I switched jobs last, but it took time for paperwork to be processed, so of course I would pay up front before then. But the article reads more like the sellers dropped the ball by cutting the insurance without ensuring their former employees were properly taken care of. There is plenty of blame to lay at Intuit's feet, but it's not like the former owners of Mailchimp didn't know what everyone else knows. Sounds like they just wanted some quick cash and everything else was someone else's problem.

Didn't MailChimp employees got bad deal because they had no equity to begin with of my memory serves me right

Correct, it was entirely owned by the founders.

On the other hand, Business Insider has a giant paywall that doesn't let you view anything at all, and Slashdot links to Business Insider.