Do I really need countQuery in a native @Query for pagination?

According to the reference, countQuery is required for native queries pagination (at least there is an example with it). But according to my tests (Spring Boot 2.4.5), @Query pagination works without countQuery for such queries:

public interface ARepository extends JpaRepository{
  @Query(value = "select * from a", nativeQuery = true)
  Page findAllANative(Pageable pageable);

  @Query(value = "select count(a.id) as aCount, category.name as 
        categoryName " +
        "from a " +
        "join category on a.category_id=category.id " +
        "group by category.name",
        nativeQuery = true)
  List findACountByCategoryNative(Pageable pageable);
}

As you can see, there is no countQuery and they work.

Does pagination work only for these specific queries or I can omit countQuery in all cases?