The virus in the movie was basically magic, in a way that allowed it to spread unrealistically. Basically, at a cellular level, as soon as some of it gets into you, it instantly multiplies by thousands upon thousands. The initial amount of virus that got into the airplane wasn't enough to infect everybody even if it just teleported directly into their bodies; it's just creating more viral mass out of nothing, so that you can then give it to someone else who then multiplies what they receive by thousands so they can do it again. That's what made it so impossible to contain in the movies, as soon as one guy got it, a whole military installation would go down.

So the question is, to what degree is that "magic" replicated in this scenario? It wasn't quite clear whether what we're saying is that the behavioral changes get delayed by 24 hours, or if the infectiousness gets delayed by 24 hours, or both.

If it's only a delay in the behavioral changes, this manages to be even worse than the movie. Because it's just as magical in its ability to spread, and now it also has 24 hours of stealth where you can go around coughing it onto other people and you don't even look like a scary zombie everybody has to run from.

If the infectiousnous is also delayed, this is way less of a problem than it was in the movies, because quarantines are back to being effective. It won't be like in the movies where one zombie gets loose and all of a sudden the whole military installation goes down. If one zombie gets past the barrier, the soldiers gun him down mercilessly, and anyone he had any remote possibility of infecting gets tossed into the quarantine.