I agree with the article's main points, but I think the author gives the game's creators too much credit here. You could tell from the first trailer that this game was going to engage in historical revisionism of the "the Vikings were really noble heroes" type. This isn't oversight or subtext, it's a conscious and deliberate choice.
The people who made this game weren't stupid or ignorant. If they chose to erase the reality of Viking slavery and violence against defenceless civilians, it wasn't an accident. They may (or may not) have intended to defend colonialism in general, but this game is an entirely intentional attempt to defend _Viking_ colonialism specifically. And they will have been perfectly aware that this played into neo-Nazi tropes.