Does it really matter to the end-user how incredibly difficult the fix may or may not have been? You've got a gigantic effect that is the visual and storytelling focus of the major attraction in the newest park on property that is promoted in its original full-moving glory to this day in advertising in and out of the parks. It should have been fixed as soon as possible. I completely understand why they are fixing it the way they are (on 3rd shift, with no fanfare and no closure) given that a CM told me in January that most people don't notice the difference (an explanation I actually believe given how inattentive most people are to details in general, not just at Disney parks). I don't doubt for a minute despite all my misgivings about the way the parks have been neglected (in my opinion) in recent times (which appears to be slowly turning around, thank goodness) that they would have fixed it day one if they could have.
Bottom line in my opinion is, if something, no matter what, is broken, you fix it as quickly as possible while still keeping (general) customer (dis)satisfaction as your number-one priority. Is this case, they appear to have done a good job. They get a pat on the back and can move on to the next issue.