I will always applaud a person who retreats — even just a little — from dogma and fanaticism.
https://www.npr.org/sections/parallels/2013/05/29/187009384/...
It's quite a bit above our pay grade to proclaim categorically who supposedly cannot be redeemed; it verges on blasphemy.
Cf. Job. 38:
1. Then the Lord spoke to Job out of the storm. He said:
2 “Who is this that obscures my plans with words without knowledge?
3 "Brace yourself like a man; I will question you, and you shall answer me.
4 “Where were you when I laid the earth’s foundation? Tell me, if you understand.
5 "Who marked off its dimensions? Surely you know! Who stretched a measuring line across it?
6 "On what were its footings set, or who laid its cornerstone—
7 "while the morning stars sang together and all the angels[a] shouted for joy?"
(etc.)
https://www.biblegateway.com/passage/?search=Job%2038&versio...
And the idea that atheists can be saved isn't novel in Catholic teaching – it is implicit in the Holy Office's 1949 condemnation of Feeneyism, [0] in which it declared that a person who doesn't believe in Catholicism due to "invincible ignorance" can be saved by an "implicit desire" for God. Although it didn't include the case of atheists, it didn't exclude them either – suggesting that an atheist who doesn't believe in God in their head (due to some intellectual issue) but nonetheless believes in God in their heart can be saved.
Hence, anyone who loves Good loves God... so a person who truly loves Good, but who due to some intellectual obstacle, isn't able to call that Good "God" – from a Catholic viewpoint, it can be said that they love God without knowing that it is God whom they love – and by that love they can be saved
If you start from the assumption that Christianity is true, and some people know this, and others don't – you have to ask why the people who don't know it, don't know it. And this is where Catholic theology distinguishes between "vincible" and "invincible" ignorance - "vincible" means the ignorance is your own fault, "invincible" means your ignorance is through no fault of your own.
How to distinguish the two? Ultimately, it is up to God to decide – nobody else knows for sure what's going on in your head. At best, theologians would give some examples of hypothetical situations which could be said to be one or the other – but the real world is often much messier than any such hypothetical can capture.
Which is part of why, the traditional Catholic teaching, is that (with rare exceptions) you can't actually know where people are going to end up. The idea is that if you make it to heaven, you might be surprised to find a lot of people there you weren't expecting, and also maybe some people you were sure would be there aren't.