"Turaga, maybe it's just from me living in this volcano for so long, but for a few years didn't I used to be called Jala? But then you changed my name to Jaller and told me that's how it always was, and it's just kind of confusing. When did I initially change it, why did I do it, and why the sudden need to change it back and then forget it ever happened? Hewkii and Macku said they had similar experiences."

"Look, don't think too hard about the Naming Day stuff; just be glad you'll eventually get made into a named set without cultural appropriating. Now, who's up for a fun game of Kolhii?"

Yeah, lol.

For real though, we can assume Takua deliberately named himself Takanuva as a tribute to the Toa Nuva. Under different circumstances (and we know an infinite number of those exist canonically) he may very well be Toa Takua.