Exactly, there is a huge difference, that's the point!
You seem to think the original claim is that someone took code from CDO and built AWS off of it, and no one said that. The simple claim which is reinforced in the very Quora link you provided is that Amazon had developed expertise in delivering computing infrastructure internally, and decided it would be profitable to offer this service externally.
Your claim that most people have a very specific belief about an implementation detail regarding whether literal code was reused or transferred is almost certainly false. The belief is that a company that developed expertise in an area that proved to be invaluable internally managed to leverage that expertise into a new product line that they could sell to other people, and nothing you have provided contradicts that.
AWS was obviously not going into building datacenters and taking a modern service oriented architecture approach cold. But, as you say, the pervasive myth is that AWS started out by using excess retail computing capacity and presumably the same architecture which, by all accounts, is simply untrue.
And GCP more or less started out as a classic PaaS. Azure really had more of an on-prem focus at first.
You seem to think the original claim is that someone took code from CDO and built AWS off of it, and no one said that. The simple claim which is reinforced in the very Quora link you provided is that Amazon had developed expertise in delivering computing infrastructure internally, and decided it would be profitable to offer this service externally.
Your claim that most people have a very specific belief about an implementation detail regarding whether literal code was reused or transferred is almost certainly false. The belief is that a company that developed expertise in an area that proved to be invaluable internally managed to leverage that expertise into a new product line that they could sell to other people, and nothing you have provided contradicts that.