The announcement ( https://forums.galaxy-of-heroes.starwars.ea.com/discussion/180392/game-update-8-30-2018-mods-2-0#latest ) sounds like it might be permanent indeed: "Increased Hard Node Attempts: Hard Nodes attempts have been increased from 5 to 8"
However the ingame message was the same as last time ("For a limited period of time..."). Maybe a copy&paste issue but I'd rather not count on it being a permanent change. Could be disappointing like last time ( https://forums.galaxy-of-heroes.starwars.ea.com/discussion/172259/y-reduce-hard-nodes-from-8-to-5 )