It’s also very simple - and a bit more logical - to say the fingers are canon. Also, Tahu Mata either had fingers or two prongs coming out of his hand for literally no reason at all.
Going the route of no fingers, there’s a lot of design elements I had previously mentioned that become extremely awkward if they don’t represent fingers, like 2/3 of the Toa Mata, all Tohunga, Teridax, Ultimate Dume, Gadunka, and many others - and if the Mata have fingers and the Nuva don’t, then you have an even greater difficulty on your hands, because now energized protodermis takes fingers.
Clearly what he is saying is that MU residents don’t have fingers and then getting annoyed when someone says they clearly do. This was 2015 Greg, who seems to forget he wrote Chiara and Mutran specifically having fingers and implying the existence of such every time he wrote a character making a fist, because that requires fingers, too.
Which reminds me, the Toa Mata/Nuva bumped fists often. Lesovikk’s team is stated to have been bumping fists in Lesovikk’s illusion. Guess they have fingers, then.