To be clear, I don't believe any atheists can be saved.
The meaningless formula thing comes from an encyclical from Pope Pius XII. Which as far as I understand, wouldn't be infallible. So I'm not sure how that could be used to determine that particular views of EENS are heretical.
And to be clear, again, I'm not defending Barron, just trying to understand how exactly we're distinguishing heresy (outright condemned by the Church) with merely extremely implausible imprudence
Interestingly, Mgr. Fenton seems to have regarded Humani Generis'
reference to tautological EENS to be the Holy Father taking a swipe at Saint Benedict's Center, or at least he leveraged the expression against them in his famous "The Meaning of the Church's Necessity for Salvation" article in 1951.