Clarify primary/fallback autowiring for arrays/collections/maps

Closes gh-32301

spring-context/src/main/java/org/springframework/context/annotation/Fallback.java

@@ -29,6 +29,11 @@ import java.lang.annotation.Target;
  * <p>If all beans but one among multiple matching candidates are marked
  * as a fallback, the remaining bean will be selected.
  *
+ * <p>Just like primary beans, fallback beans only have an effect when
+ * finding multiple candidates for single injection points.
+ * All type-matching beans are included when autowiring arrays,
+ * collections, maps, or ObjectProvider streams.
+ *
  * @author Juergen Hoeller
  * @since 6.2
  * @see Primary

spring-context/src/main/java/org/springframework/context/annotation/Primary.java

@@ -27,6 +27,10 @@ import java.lang.annotation.Target;
  * are qualified to autowire a single-valued dependency. If exactly one
  * 'primary' bean exists among the candidates, it will be the autowired value.
  *
+ * <p>Primary beans only have an effect when finding multiple candidates
+ * for single injection points. All type-matching beans are included when
+ * autowiring arrays, collections, maps, or ObjectProvider streams.
+ *
  * <p>This annotation is semantically equivalent to the {@code <bean>} element's
  * {@code primary} attribute in Spring XML.
  *