That's interesting. I remember from the commentary of Mask of Light the makers of the movie were also told Toa were about 6ft tall IIRC, but in another source (according to BS01 it's the "BIONICLE: Encyclopedia Updated") Toa are about 1.6 bio tall meaning the average Toa height is around 219 cm/ 7'2".
I found this Greg answer from 2010, where he also says Toa are about 7'2": https://greg.thegreatarchives.com/2008-2010/page262#post10447
In this 2003 answer, he says "I believe, roughly 6 feet tall": https://greg.thegreatarchives.com/2003-2008/page2#post64
He also says if you want to know Matoran heights, comparing the Matoran sets of a particular year to that year's Toa is a decent way to gauge it.
Here (2004) he says Matoran are a third the height of Toa, half at most: https://greg.thegreatarchives.com/2003-2008/page41#post1618
Here (2008) he apparently said 4.5ft "sounds right" for average matoran height, but that is over half the height of the average Toa... : https://greg.thegreatarchives.com/2008-2010/page104#post4134-line29
Regarding Matoran, it's worth remembering that some of the sets we got represented weakened/buffed Matoran. For example, the 2001 McToran were smaller because they were weakened by the Matoran Spheres. The Voya Nui Matoran were smaller because they were badly fixed by Karzahni, and the Av-Matoran in Karda Nui were bigger than normal because the energy in Karda Nui makes Av-Matoran and Toa of Light get bigger. So the 2003 "Rebuilt" Matoran, the 2004 Metru Matoran, and the restored-via-Pit-Mutagen 2007 Mahri Nui Matoran are the ones that should be most representative of normal average Matoran heights. In general, from what I can tell, normal Matoran are about 4ft tall.
1. So Greg, which one is right? Is the average Toa height about 6ft or 7ft 2in?
2. What about Matoran? Would you stick to the "compare them to the Toa sets of their year" principle?