I don't believe they've come with it themselves.
Well no, and they are not the first to use zero knowledge proofs or KVACs either. But neither was Satoshi the first to use proof-of-work, Merkle trees, or elliptic curve cryptography.
Yeah, but applying Pedersen commitments
to blind amounts is exactly what Monero has done before.
Meanwhile satoshi was the first to
apply PoW, Merkle tress and EC cryptography to create a decentralized currency.