No, not really. The config checker is an entirely optional part, and I was not even aware it existed.
This situation is like “Ford dealership installed wrong tires on Ford truck when customer asked for them, causing an accident”. Yes, it is the same people, and the car ended up on the ditch, but I wouldn’t call this “problem with the car”
Fair enough, I did not read the article too carefully, and thought that the config checker was the part of sshd that validates the configuration when the daemon is starting.