From a 1 dimensional viewpoint, what you said is true. However both are still available whether you nuke the OP_RETURN filter or not.
Bitcoin is money, and the idea of facilitating and accommodating spammers is the most anti-cypher punk thing I have ever heard. Any type of spam can be mitigated with a filter, don't be gaslight to believe otherwise. It's just one game of whack-a-mole we need core to play here.
Keep learning man, you're doing the work that most won't bother to do 💪
Do you maybe know what is meant by the opreturn being provably prunable? Does that mean only pruned nodes discard this data? Or do all nodes ditch it at some point?
Or in other words, a new node that is syncing, will it fetch this data or ignore it?
Still didn't figure this part out :)
The UTXOs are definitely never going to be spent, known as 'provably unspendable', so can effectively be forgotten about by a pruned node. A full node would still store them on the other hand.
A new node syncing will check through everything including the provably unspendable utxos, but once verifying the transaction information eg signatures etc, it will remove the data from memory.
