I haven't spent much time with Next.js, but luckily React will soon natively support[0] SSR. Wonder if Next.js will still be around once React Server Components are fully released.
In short, the answer is likely yes. React's server component stuff is about providing primitives to make it possible to address some of the downsides of the current approach to building apps/sites that follow the SSR-with-SPA-handover (hybrid rendering) model. There'll still be a need for more holistic frameworks that sit in front of React. SSR itself has been possible with React since 2014 (allowing for a few memory leaks), Next.js just eliminates a lot of the grunt work.
The React team is working with the Next.js team (amongst others) to make sure there's alignment.
The React team is working with the Next.js team (amongst others) to make sure there's alignment.