I see a lot of "allegedly" in that article without any resolution. The government claims the companies knew since the 30s, but they say otherwise, and the article doesn't seem to include proof either way. I'm not surprised the government would allege that either, as the alternative is yet more evidence of how poorly run NNSY was (and frankly still is).
As an anecdote, we still find asbestos on ships built in that era. It'll be another several decades until we stop finding it.