No, it really depends. It's easy to overlook stuff on a merge request. I'd interview both of the reviewers, and with them look at the actual MR and see what they were looking at, and ask them how they missed this and why they thought it was OK to merge.

I've seen some pretty glaring stuff get through a review process, particularly with junior engineers.

Everywhere I've worked, "signing off" on the changes just meant we were OK with the technical implementation. Unless you were junior, you were trusted to have approval for the purpose of the change.

A change like this, which was linking to an official policy document, wouldn't have raised any eyebrows.