ESB and ROTJ Yoda, the slight rearrangement of words was a quirk, and it was subtle enough to not seem forced.
Prequel Yoda is the product of 20(at the time) years of fans speaking backwards, so George thought that was the only way to write Yoda. It’s also possible Frank Oz was equally as guilty, but I doubt it. “Frank…talk backwards, you must. Notice it, fans will.”
It’s basically the caricature becoming reality.