Update release notes

CHANGELOG.md

@@ -351,6 +351,14 @@ In order to use your build-time loader data during pre-rendering, we now also ex
   - We previously only disabled this for "SPA Mode" but we realized it should apply to all `ssr:false` apps
   - In those `prerender` scenarios we would pre-render the `/__manifest` file but that makes some unnecessary assumptions about the static file server behaviors
 - `react-router` - Don't apply Single Fetch revalidation de-optimization when in SPA mode since there is no server HTTP request ([#12948](https://github.com/remix-run/react-router/pull/12948))
+- `react-router` - Properly handle revalidations to across a pre-render/SPA boundary ([#13021](https://github.com/remix-run/react-router/pull/13021))
+  - In "hybrid" applications where some routes are pre-rendered and some are served from a SPA fallback, we need to avoid making `.data` requests if the path wasn't pre-rendered because the request will 404
+  - We don't know all the pre-rendered paths client-side, however:
+    - All `loader` data in `ssr:false` mode is static because it's generated at build time
+    - A route must use a `clientLoader` to do anything dynamic
+    - Therefore, if a route only has a `loader` and not a `clientLoader`, we disable revalidation by default because there is no new data to retrieve
+    - We short circuit and skip single fetch `.data` request logic if there are no server loaders with `shouldLoad=true` in our single fetch `dataStrategy`
+    - This ensures that the route doesn't cause a `.data` request that would 404 after a submission
 - `react-router` - Align dev server behavior with static file server behavior when `ssr:false` is set ([#12948](https://github.com/remix-run/react-router/pull/12948))
   - When no `prerender` config exists, only SSR down to the root `HydrateFallback` (SPA Mode)
   - When a `prerender` config exists but the current path is not pre-rendered, only SSR down to the root `HydrateFallback` (SPA Fallback)
@@ -365,6 +373,13 @@ In order to use your build-time loader data during pre-rendering, we now also ex
   - `loader` functions are more nuanced and depend on whether a given route is prerendered
     - When using `ssr:false` without a `prerender` config, only the `root` route can have a `loader`
     - When using `ssr:false` with a `prerender` config, only routes matched by a `prerender` path can have a `loader`
+- `@react-router/dev` - Error at build time in `ssr:false` + `prerender` apps for the edge case scenario of: ([#13021](https://github.com/remix-run/react-router/pull/13021))
+  - A parent route has only a `loader` (does not have a `clientLoader`)
+  - The parent route is pre-rendered
+  - The parent route has children routes which are not prerendered
+  - This means that when the child paths are loaded via the SPA fallback, the parent won't have any `loaderData` because there is no server on which to run the `loader`
+  - This can be resolved by either adding a parent `clientLoader` or pre-rendering the child paths
+  - If you add a `clientLoader`, calling the `serverLoader()` on non-prerendered paths will throw a 404
 - `@react-router/dev` - Limit prerendered resource route `.data` files to only the target route ([#13004](https://github.com/remix-run/react-router/pull/13004))
 - `@react-router/dev` - Fix typegen for repeated params ([#13012](https://github.com/remix-run/react-router/pull/13012))
   - In React Router, path parameters are keyed by their name, so for a path pattern like `/a/:id/b/:id?/c/:id`, the last `:id` will set the value for `id` in `useParams` and the `params` prop