I'd say Chevron deference is almost certainly dead this term, but I wouldn't expect it to make much if any difference to things like this "national security" stuff. Here especially, this court springs from an executive order so Chevron probably doesn't even apply to it (maybe in a more narrow sense like, is there authority to even have the court in the first place).

Chevron's an interesting one... personally I'm for retaining it, but it's another of these cases where its outsized importance is just a symptom of the broken state of the government. Chevron deference only applies where Congress has delegated power and the statute is vague, so Congress has a simple and obvious route to overriding or correcting any undesired actions by the agencies that rely on Chevron to be upheld. But with substantive lawmaking so seemingly impossible now for such a long time, the executive and the courts have gained more and more practical power. Keeping or killing Chevron is all about just shifting the balance of power between the judicial and the executive, with the legislature standing idly by. Part of the problem is that Congress is happy to allow this to happen, to reduce their workload and their accountability.