Correct, we're shipping with an initial version of React Server Components (RSC) that works in Vite and uses file suffixes. Hydrogen provides missing pieces to the current version of RSC, like data fetching and other dev tooling.

We're working to align with Vercel on improving the conventions of server modules (e.g. dropping the filename suffix): https://github.com/reactjs/rfcs/pull/189#issuecomment-111648... and we anticipate to release future versions of Hydrogen and Next.js that use something like boundary annotations instead.