I think you are confusing UTXO and unconfirmed transactions. The UTXO set is all confirmed transactions that have unspent outputs.
Edited the original post, is my question clearer now ?
why edit the original post rather than clarifying the matter in a subsequent post?
A lot of this blocksize debate seems to be speculative with a lot of potential solutions with NONE Of them being real detrimental to the overall health of bitcoin, except possibly mostly for the creation of FUD and downward price manipulations.