I am excited about the privacy and optimisations involved with moving from ECDSA to Schnorr signatures. One of the privacy improvements, as I understand it, is that you can aggregate signatures so instead of revealing the keys involved in a multisig transaction you would only see one key / signature as an input which is the sum of multiple inputs.

But how would this appear in the UTXO set?

If, for example, I have UTXO-1 and UTXO-2 and wish to consolidate them: when I construct the transaction with Schnorr, would UTXO-1 and -2 'disappear' from the UTXO set and the new aggregate signature just appear as an input?

How would this appear in a block explorer?