And lo, Mata Nui instructed Dume to send his Vahki to cleanse Metru Nui of all sin and inefficiency. But Dume didn’t want to spend time on programming or moderators, so he had Nuparu cobble together a shoddy recognition code to flag anything looking remotely like smuggling or idle workers.
Sadly, the Vahki flagged and destroyed all the Po-Matoran, because they were dune colored.
Takua was untouched because his colors had been slightly altered and the filter couldn’t recognize him.
That is Literally what Nuju does in bionicle. When introduced he is a wise old man figure who speaks the language of birds and requires a translator.
Later in a prequel story arch its revealed he spoke the same language as everyone else perfectly fine, but out of spite stopped. Afterwards he only spoke one word in their language once and it was more or less as an ominous foreboding message.
While I whole-heartedly support the switch from “Tohunga” to “Matoran”, there was definitely a period of time where young me thought they had for some reason decided to name the entire species after that one Ice villager