Is there any evidence that this makes a difference? Or is even important?
While it may be important for schools to insist on a teaching degree if, for nothing else, to try to weed out the incompetents, I can see no extra benefits on insisting on them for pre-K.
The state classes that my wife was required to complete to get a CDA certificate stressed how it was wrong to try to teach skills that were too advanced, and this means that bright kids are prevented from learning in the public settings because those skills are not allowed to be taught.
So, to answer your questions: No on both counts! Sometimes it is even an impediment to learning.