UPDATE:
To complete the “swap” process, a similar swap authorization is required to be made on behalf of the Moonelement parachain (ID 3342). The Moonbeam team had planned to start the Moonelement parachain and initiate a similar XCM message to be sent to the relay chain.
Unfortunately, there was a misconfiguration in the genesis head that was submitted along with the WASM when the parachain was initially registered. The Moonbeam technical team has determined that starting Moonelement will not be possible.
For this reason, the Moonbeam Foundation has created Polkadot OpenGov Referendum 139 which, when passed, will execute the registrar.swap extrinsic on behalf of the Moonelement parachain.
See forum post here: