Not sure how NextJS handles async component SSR, but looks like from the docs we should just be able to use React.lazy in place of loadable-components in an SSR render pass now. The new server components seem to be a different feature not directly related to regular SSR usage. I think they added that for people who aren't using GraphQL for data-fetching, so that certain components can be rendered on the server only and set in a serialized form without sending the associated JS required to render it.