This would allow Dash to be used on THORChain's cross-chain asset swap DEX. It would also allow dash users to provide liquidity and have another way to earn with their Dash.
This also seems to be the cross-chain liquidity provider that companies like Shapeshift are using for their new DEX platform.
In the long term, I believe that users will trade cryptos almost entirely on DEX's. We will want Dash to be available on as many as possible, and THORChain is positioned to be one of the larger providers of this service.
“To add a new chain, adapt one of the existing modules to the new chain, and submit a merge request to be tested and validated. Once merged, new nodes can start signaling support for the new chain. Once a super-majority (67%) of nodes support the new chain it will be added to the network.”