Maybe technically it's more like hashing? Regardless, the practical effect is the same since it's a string of indecipherable and seemingly random characters that are seen once and never again. Third parties can't link a stealth address to a public address off-chain or to any other stealth address.
> He's wrong about unencrypted receiver (or meant something else)
I meant what I said: monero does not encrypt the receiver. If it did, monero devs could tell me what encryption standard they use (in lightning, we use the Sphinx encryption standard specified in bolt4) and they could point me to the code where the recipient's key gets encrypted (in lightning, that code is here: https://github.com/lightningnetwork/lnd/blob/b068d79dfbd2f583d890fd605953d0d4fb897a27/htlcswitch/hop/iterator.go#L114)
Monero does not encrypt the recipient's public key -- it gets published in plaintext on the blockchain -- so the protocol does not specify any encryption standard for that and there is nothing in the codebase where it gets encrypted.
Discussion
It's diffie-helman which does involve hashing but only as a layer of protection and the most significant thing doing the unlinking is the diffie-helman computation.