> Taking a step back, why would they even care if their platform is supposedly neutral and not responsible for the content ?

Because their main network all uses one big IP address pool and the blocks by various regions/countries against their site were probably not just DNS blocks but also IP address blocks.

So they now have an account whose activity is getting their IPs banned in countries where they operate.

So they told the account owners they needed to pay for an enterprise account and a dedicated IP address pool maintained by cloudflare. That's why CF kept talking about BYOIP in the emails.

i.e. "Pay for us to build you a quarantine with your own IP pool or leave ASAP"

This may indeed be the motivation but, at least in those emails that are presented in the linked post, there's no evidence that Cloudflare did at any point clearly communicate that this is indeed what the problem is.

> Not sure it's really in their best interest to self-police in the end, as they could lose their DMCA safe harbor provision ?

This.

That said, we're seeing this across so many platforms, from datacenters to social network sites.

They blew their safe harbor provisions years ago and yet remain untouched despite this.

It’s not “editorial” to choose to stop serving (or charge more money to) a customer whose actions pose legal difficulties or risks to your business. If some country’s vice division contacts cloudflare legal due to a customer’s illegal online gambling presence, I guarantee that cop does not care about a US/EU copyright law.

The same thing is true for IP reputation, just without an external official complaining. If other CF customers are negatively impacted by one customer’s action, CF isn’t violating safe harbor by booting that customer or passing on the costs of mitigating that impact. That’s just running a business, not exercising editorial review of hosted content in violation of safe harbor provisions.