I will admit to having no knowledge at all about fountains, however, the question comes to my mind that we all seem pretty sure that what we are seeing are "plant" sprinklers. Are we sure that they haven't always been part of the fountain? And that they provide another service such as a drain or something. As I said, I don't know I just wonder how many fountain degrees are among us here on WDWmagic. As I said... don't really know I just sometimes question what we think we are seeing.
Another possibility is that they just don't want to run it as a fountain right now because of all the construction in the area that might at any given time interrupt service, but, since there is water piping there hooking up a sprinkler for the plants would save having to send a water truck to that location everyday and the labor to water them. Could be something just that simple. So, long story short, if when the construction is all done and we still have no operating fountain, then we might be able to say, without fear of contradiction, that they have decided to deactivate it.