How faithful the new effects are versus the old ones is really up to the producers. They could copy each shot exactly using CGI, and reproduce the mistakes as well, but I don't find that particularly satisfying, know that they could very well have gone and changed it and make it make sense in-universe. Defiant having the wrong registry is just plain lazy. It's because they had to use stock footage, so I forgave it, but to do it again? When they're redoing all the shots anyway? Seems criminal to me.
It's somewhat ironic that it's the "fans" who are most against updating the effects, whereas the general public either wouldn't notice or wouldn't care.
Since the effects have to be redone anyway, the marginal cost of some new shots (i.e. as opposed to stock footage) would be negligible versus the cost of the whole project.