I update infrequently. Whenever I get time to sit down at my DAW computer, I don't usually feel like installing new stuff. I end up working on projects instead.

In the Control Center I have green dots on the Big Fish Audio Loops and Sonar.
I can click on the re-install. Why are they asking me to do so? Is it wise to do so
periodically? 
 
The re-install button has a drop down menu arrow but is is not for a drop down menu
as I found out when I clicked on the arrow.  

The Command Center is not making a recommendation. The Command Center shows a "Reinstall" button because it is the only feature available after the product is installed. One reason to reinstall would be if files were accidentally deleted. There is no reason to periodically reinstall.