The multiple address output there is misleading and never should have been added in the first place.

The multiple addresses mean that it is a multisig so that txout requires some number (defined by the scriptPubKey) of the specified pubkeys to sign the spending transaction. There are no multiple UTXOs nor does the UTXO magically split for the cosigners. It is a single UTXO that requires multiple people to spend it. It's the same thing as a normal multisig in a P2SH or P2WSH, just that the "redeemScript" is in the scriptPubKey of the output, rather than the hash of it.