I don't think the chainstate folder on a pruned node requires the entire blockchain to be again downloaded if op deletes only a chain state folder. No? Yes, but only requires if he delete block's folder.
All I can say is, you're wrong with that assumption. To recreate or reconstruct the current UTXO set aka chainstate the node has to start from Genesis block and follow all transactions on the blockchain, unless you have a UTXO snapshot, e.g. created at a certain blockheight with Bitcoin Core's
dumptxoutset command, which could be loaded later with
loadtxoutset.
Loading a UTXO snapshot only gives you a defined starting point from a certain blockheight when the snapshot was saved. You still have to follow the blockchain from there block to block, transaction for transaction to get to the current UTXO set at current blockchain tip.