Add comment explaining use of fetchOnFirstSubscribe

src/react/hooks/useSuspenseQuery.ts

@@ -220,13 +220,21 @@ function useWatchQueryOptions<TData, TVariables>({
 
     return {
       ...watchQueryOptions,
-      fetchOnFirstSubscribe: false,
       query,
       errorPolicy:
         errorPolicy || defaultOptions?.errorPolicy || DEFAULT_ERROR_POLICY,
       fetchPolicy:
         fetchPolicy || defaultOptions?.fetchPolicy || DEFAULT_FETCH_POLICY,
       notifyOnNetworkStatusChange: suspensePolicy === 'always',
+      // By default, `ObservableQuery` will run `reobserve` the first time
+      // something `subscribe`s to the observable, which kicks off a network
+      // request. This creates a problem for suspense because we need to begin
+      // fetching the data immediately so we can throw the promise on the first
+      // render. Since we don't subscribe until after we've unsuspended, we need
+      // to avoid kicking off another network request for the same data we just
+      // fetched. This option toggles that behavior off to avoid the `reobserve`
+      // when the observable is first subscribed to.
+      fetchOnFirstSubscribe: false,
       variables: compact({ ...defaultOptions?.variables, ...variables }),
     };
   }, [options, query, defaultOptions]);