"National level" is a bunch of nonsense. There are events. Some are larger than others.
It doesn't make sense. Why are large cons "national", and small cons are "regional", even though they are fundamentally the same? The only difference is size. There are fan-run, and industry-run cons. Anime Expo is about the only industry-run anime con.
Panels hasn't even opened. So not likely. An Evangelion panel is well within the realm of possibilities, but it won't be tentative or official for a while.