well now you're assuming virtualization is the same as cloud, it is not, a cloud researcher should know what a "cloud" actually is instead of the marketing usage for it.
for one, redundancy is always implicit in any cloud solution.
I don't believe redundancy, what I think you mean---fault tolerance---is implicit in the definition of cloud computing.
The most general form of the term 'cloud' in my mind is elastic access to computational resources.
There is no guarantee of high availability (in fact, we see failed AWS instances and horror stories all the time), nor automated failover/redundancy/fault tolerance.
Chaos Monkey by Netflix is a great example of the shortcomings of the modern cloud in terms of fault tolerance and redundancy.
The cloud doesn't give it to you, you have to build that yourself.
I'm a very open-minded person, perhaps because of my academic background, so I would be happy to say that I agree that a subtype of the fundamental cloud could be a redundant/fault-tolerant one.
But the fundamental definition of cloud does not include fault tolerance.
Don't trust me.
Check out the more formal definition from US NIST (years of work, 15 drafts), there is no mention of redundancy or fault-tolerance:
