In the time of Ahadi's reign (in 'A Tale of the Two Brothers') hyenas seemed to be allowed to stay in Pride Lands, as far as they don't break 'the law of the land'. Ahadi blamed them for not being in the Pride Lands, but breaking the law that prohibits to kill for sport.
But TLK movie, Zazu (actually Gopher) reported Mufasa "Hyenas! In the Pride Lands!" and Mufasa immediately went off, though he was playing with Simba. It is like the hyenas are kind of trespassers.
I wonder when they were supposed to be out of the Pride Lands?