The answer to your question as stated is that if you connect directly to a miner which accepts that transaction type, then you can get those transactions in their blocks. Just because some nodes won't relay doesn't mean other nodes won't include it in their blocks.
Given we know this tx did get relayed, if we want to send out OP_RETURN tx's, is there a way to do so? I have figured out how to construct such a message properly, but it seems to be impossible so far to send it out, as expected. The typical "entry points" to send the raw tx (such as blockchain.info's push or bitcoind's sendrawtransaction) tend to fail. The latter fails client-side, I think and does not even bother talking to the network.
Perhaps the IP of the node that relayed this example tx successfully is a miner that does accept such tx's?