RE: what can you say about this?
Yes I know about delamination. And if you have a good lay-up it is not really an issue.
If you look in your photo again at the shock tower, I made that. There are about ten of them floating around the world and I have never heard anything about them delaminating. I never sealed the edges
To answer your question, no, OFF does not seal their edges. I don't know of a single CF parts manufacture that does. I imagine it would be time consuming and simply raise the cost of the parts. As you can see from the link you posted it is a simple process that anyone can do.
I don't think that delamination was the culprit here. It looks to me the the part broke along the narrowest and weakest section.