The paper only applies to "special integers" where the prime factors are known to only differ by two bits.
Though it's poetic justice that OpenAI is complaining about someone else playing fast and loose with copyright rules.
[ my public key: https://keybase.io/kkwok; my proof: https://keybase.io/kkwok/sigs/5qGM4MGK91WsEYGjQRq6h0oHCn4i8PZaN8gq4FonTRM ]