Veterans are immune to isolation. When isolated, comms attacks, such as hacking are disabled. N4 no longer has a pure comms disabled state (Blackout is gone; it’s all Oblivion now). It looks like Veteran Hackers can’t be stopped from hacking, regardless of how much E/M ammo they are blasted with. Is this the desired effect?
Note that this hasn’t actually changed between editions. Veteran in N3 ignored the whole of Isolated State, N4 just made it clearer by saying that they don’t even enter the State. N3 Veteran, last bullet: The user ignores all the Isolated state effects (caused by E/M Special Ammunition, the Oblivion Hacking Program, scenario special rules, etc.). Notably, in Hunting Party, being ‘hunted down’ due to being in Isolated State was ruled to be an ‘effect’ of Isolated State, so you had to IMM them instead.