The history of Who (of most sci-fi in fact) is replete with alien races using human terms/titles, but they rarely mean the same thing as they do on Earth.
The Daleks also had an Emperor, the Timelords had a President and a Castellan and a Chancellor, the Sontarans have generals and commanders…
The word parliament comes from the French parler, which means to talk or to discuss. So rather than imagine this is a Dalek Westminster, perhaps it’s just the Skaro University debating society?
(And yes I cribbed that last bit from Wikipedia…well apart from the Skaro University debating society obviously