Is it your prediction or what? Do you have any proof about this services and his ban reason?
I saw threads posted by OP himself related the so-called ban of crypto/bitcoin-related accounts about
ConstantContact and
SendInBlue. But upon searching in google, I didn't see any article related to this except for the mailchimp which I mentioned already.
Because of many ICO scams, all paid advertisements are now under observation. I am not sure for Bitcoin specifically.
Yes, mostly it's because of ICOs or any investments schemes not in bitcoin particularly.
Mailchimp and other email marketing services are always under the control. they must strictly abide by if they want your service to keep alive.
I know several Twitter accounts who are directly offering "Twitter advertisements" to his follower audit, now they are banned.