Ordinals is not part of the Bitcoin protocol to be "rolled back", it is garbage that people are injecting into the blockchain by exploiting the protocol which means the only way to "roll it back" is to reverse the blockchain which is not possible because it would effectively eliminate one of the basic principles of bitcoin: immutable blockchain.
The only way to battle the Ordinals Attack is for the nodes to start rejecting these spam/abusive transactions but unfortunately nodes need to be patched to give the node users this choice and that is not happening since the developers aren't really interested in doing that much to prevent this attack!
I fully support any actions taken against this attack though, even if the mempool were empty. Because it is still abusing the protocol.