Um, no, not then, either.
Why would it be altered?
Because someone, at some point, thought it was a good idea to obscure info before posting it on the Web. Whether obscuring the certificate number was necessary or not, someone thought it was a good idea.
First of all, redacting a document is altering it, therefore it becomes invalid. Second, the cert number is a means to validate the said document, that number leads to no more information then is contained on the document that is submitted as proof.
"Someone" obscured the number for a reason alright, the reason being it is a fraud, there is no other reason.
Even if it is real, what possible information is on a BC that is private or at least that the public doesn't have a right to know?