Now, I don't think I can directly point at a PF reference, but my (often faulty) memory would seem to indicate that Nugoeihuvi was originally an alliance of smaller corporations which noticed that any of the seceded corporations did not have a strong presence in the media industry and decided to grab the economic niche.
Can't remember anything of Lai Dai. Not sure if (Herko's/Raim's?) etymology (lai "forget" and dai "do not") is canon, but if it is, it would indeed suggest that Lai Dai is a post-secession or rebranded corporation. Another possible "origin story" for Lai Dai might be that of a division of a successful megacorporation losing its business niche due to the secession and the following war and then restructuring around a successful division. I am for some reason thinking about a specific Finnish pulp mill/rubber galosh factory/cable factory conglomerate that has made, amongst other things (freely quoting Wikipedia) "paper products, car and bicycle tires, footwear (including rubber boots), communications cables, televisions and other consumer electronics, personal computers, electricity generation machinery, robotics, capacitors, military communications, gas masks, plastics, aluminium and chemicals". (This "other consumer electronics" includes mobile phones.)