It seems that none of the character generation steps give out the Low Gothic specialization of the Linguistics skill as they have in the other games. Is this just a oversight or intended?

It is intended, but the reasoning for the omission is fuzzy at best. I believe it was said that Linguistics skill represents formal education in grammar and language structure rather than basic literacy, and this kind of an education isn't standard in the Imperium. Characters are assumed to read and write Low Gothic, but they can't understand ancient dialects like someone with Linguistics training.

IMO this distinction is overly fiddly. I can't remember the last time my PCs made a Linguistics (Low Gothic) check.

So everyone can read now?

Everyone or no one your choice