No, the Elektron WebSocket API will not automatically expand the underlying chains for application. A chain request will return the contents of the underlying link FIDs that can be used within your applications to issue the necessary underlying RICs requests as needed.
For more details regarding decoding Chains, I suggest you check Decoding Chains - Part 1 article which can be applied to the WebSocket API too.
We need to use the Secure protocol only, does Elektron WebSocket API support wss connection? Does TREP perform wss for us or we need to set our own SSL accelerator? (from WebSocket API Webinar Nov 29)