There is a filter in the relationship field that will allow this. There is a previous topic that covers how to use it, however, like the use in that topic it will not currently work unless you apply a similar has as the one I outlined in that post. Basically you can change the orderby to order by date but you’ll need to override the part of the ACF file that groups the posts by taxonomy.
http://support.advancedcustomfields.com/forums/topic/relationship-filter-query-by-page-template/
