I agree that as a private company they can do what they want, but I wonder if they're setting themselves a difficult precedent here.
https://mailchimp.com/legal/acceptable_use/
Every mail I receive that I didn't sign up for gets a spam report from me. With that in mind, every single ICO mail I've gotten has been spam.
>>not involved in the exchange of cryptocurrencies
... seems overkill. So any journalist who has actually transacted with Bitcoins is off the platform? That seems like mainly negative effects from the standpoint of "selecting for informed journalists".
"Sure, you can use our platform to talk about cryptocurrencies, as long as you're just one of those admire-from-a-distance types."
Ditto for production -- that would include e.g. anyone who's contributed code.
>>> It’s important to note that this update to our policy does not prevent the discussion of related topics in messages sent through our platform. For example, journalists and publications may send cryptocurrency-related information as long as they’re not involved in the production, sale, exchange, storage, or marketing of cryptocurrencies. <<<
Unfortunately, the reality is: there's a LOT of fraud associated with the production, promotion and sale of ICOs, and it's no doubt creating expense, risk, and overhead for Mailchimp.
As a private company, it's entirely proper and reasonable for them to prohibit activities that directly affect their business.