This is an EE template that has both the depreciated native EE relationship {reverse_related_entries} and Playa entries. When upgraded to EE 2.7.3, the native EE tags no longer render, even when updated to {parents:}

relationships.html

{embed=site/header}
<div class="content">

{exp:channel:entries 
channel="speakers" 
limit="1"
}
<div class="content-box">
  <img src="{speaker-identity-graphic}" alt="{title} Photo" />
</div>

{!-- PLAYA FIELDS RENDERING --}

      {exp:playa:parents channel="consultants"}
          <p class="right mrm"><a href="/consultants/{url_title}" class="tablink-orange uppercase">VISIT {consultant-first-name}'S CONSULTANT PAGE</a></p>
          <br class="clearfloat" />
      {/exp:playa:parents}      
      
  {speaker-body}
  <div class="testimonial-rotation">

{!-- EE FIELDS *NOT* RENDERING AS-IS
		 OR WHEN UPDATED TO {parents} --}  

      {reverse_related_entries 
        channel="testimonials" 
        orderby="testimonial-weight"
      }
      
	      {if title!=""}
	      <div class="testimonial-block">
	          <p class="testimonial serif oblique">{testimonial-body}</p>
	          <p class="testimonial-name-location">{testimonial-author}, {testimonial-location}</p>
	          <div class="testimonial-block-btm"><br class="clearfloat" /></div>
	      </div>
	      {/if}
      {/reverse_related_entries}
      
  </div>
  <br class="clearfloat" />
  <ul class="keynotes-list">
    <li class="list-title"><h3 class="red serif">Keynotes</h3></li>
    
      
{!-- EE FIELDS *NOT* RENDERING AS-IS
		 OR WHEN UPDATED TO {parents} --}  
   
      {reverse_related_entries 
        channel="keynotes" 
        orderby="keynote-order"
      }
      
      <li><a href="#{title}" class="grey">{title}</a></li>
      {/reverse_related_entries}
  </ul>
  <br class="clearfloat" />
  
{!-- EE FIELDS *NOT* RENDERING AS-IS
		 OR WHEN UPDATED TO {parents} --}   
  
  {reverse_related_entries
   channel="keynotes" 
   orderby="keynote-order"
  }
  
  <a name="{title}"></a>
  <h3 class="dkblue">{title}</h3>
  {keynote-description}
    {if keynote-speaker-note}
    <p class="grey">Note from the speaker:</p>
    <p class="grey serif oblique">{keynote-speaker-note}</p>
    {/if}
  {/reverse_related_entries}
  
  {if speaker-bio!=""}
  	<h3 class="red serif">{speaker-first-name}'s Bio</h3>
  {speaker-bio}
  {/if}
                      
 {if nsa =='Yes'}
	<img style="padding-left: 28px;" src="http://campuspeak.com/assets/uploads/NSA_MemberLogo.jpg" width="100" height="75" />	
	{/if}
{/exp:channel:entries}


</div><!-- end: content -->
{embed=embeds/subcontent}
{embed=speakers/sidebar-profile}
</div><!-- end: content-container -->
<div class="modal-container">
<div class="modal-content">
  <a class="closebtn">CLOSE</a>
  <iframe src="" width="340" height="260" border="0" id="modal-frame" scrolling="no">
      <p>It looks like your browser doesn't support iFrames. It might be time to upgrade.</p>
  </iframe>
</div>
</div>
<div class="value-modal-container">
<div class="value-modal-content">
  <a class="closebtn">CLOSE</a>
  <div class="value-modal-top">
      <br />
  </div>
  <div class="value-modal-mdl">
      <p><span class="dkblue bold">Get More!</span></p>
      <p>Our speakers provide value items to our customers every time they book a program at full price. These can be used as giveaways to students who attend the program, or as gifts to your hardworking student leaders.</p>
      {exp:channel:entries channel="speakers" limit=1}
      <p>With <span class="dkblue bold">{title}</span> choose from one of the following:
          {speaker-value-added-items}
      {/exp:channel:entries}
      <p class="small">Restrictions apply for additional programming and speaker value items. Please call CAMPUSPEAK for more information.</p>
  </div>
  <div class="value-modal-btm">
      <br />
  </div>
</div>
</div>
{embed=site/footer}