Ladder - Cyclone / Liberator do not have their normal voice overs

While I was playing a vs AI game, the cyclone and liberators were using a text to speech version of their voice lines instead of their normal ones.

I have noticed the same thing with the Adept as well. No other Protoss unit did it.

I find it funny that you guys noticed units doing it, because I spotted it with Donny Freaking Vermillion at the end of The Vermillion Problem. He was saying a line I had never heard before, too - maybe it has something to do with missing voice files?