An interesting question, so time for some 100% speculation.
It sounds like they probably have revenue in the €500mm range today. And given that the bare metal cost of AWS-equivalent bills tends to be a 90% reduction, we'll say a €10mm+ bare metal cost.
So I would say a cautious and qualified "yes". But I know even for smaller deployments of tens or hundreds of servers, they'll ask you what the purpose is. If you say something like "blockchain," they're going to say, "Actually, we prefer not to have your business."
I get the strong impression that while they naturally do want business, they also aren't going to take a huge amount of risk on board themselves. Their specialism is optimising on cost, which naturally has to involve avoiding or mitigating risk. I'm sure there'd be business terms to discuss, put it that way.
Why would a client who wants to run a Blockchain be risky for Herzner? I'm not a fan, I just don't see the issue. If the client pays their monthly bill, who cares if they're using the machine to mine for Bitcoin?