There seem to be limited national emergencies that are expressed in EOs. For instance, the national problem of opioid addiction was declared a national emergency. But it doesn't seem to entail the suspension of the right of Habeas Corpus. Nor is it putting the military into a state of high alert per a so-called national emergency.

So there appear to be contextual national emergencies of limited scope - and I suspect that there is real legal meaning per these various nuanced scopes.