LANGUAGE - Learning about labial-less languages

I was curious (amongst other things) in a previous blogpost about why only north American languages seem to lack labial sounds. My thanks to a good acquaintance of mine who sometimes goes by the moniker of OPB for the following information:

The most famous American family to lack bilabials is Iroquoian; in fact, the proto language doesn't even have bilabials. This has been attributed to any number of things, including lip jewelry (such as labrets) that made bilabials difficult; and such was common among traditional Iroquoians. Interestingly, some Iroquoian languages like Mohawk have acquired /p/ and /m/ as periphreal phonemes in some loanwords from English and French; you see them in Biblical names like _Aplam_ (Abraham) and _Umali_ (Mary), and in words like _majis_ (matches). Why such occurs in N. America and nowhere else, I don't know; I don't think anyone does.

Northern Iroquoian lacks not only bilabial consonants, but rounded vowels are typically only very weakly rounded; Mohawk /u/ and /o/, e.g., are very close to [ɯ] and [ɤ] (with the former always being a nasal vowel). Mohawk /w/, too, is far more velar than labial. Whatever historical processes are responsible for delabialization in the family seem to have rolled over consonants and vowels alike.

Thanks OPB. If anyone who happens by this blog can share information and shed some further light on this, I'd be most grateful (as would be OPB too, I would presume).

Furthermore, in my focus on my own painful experiences with labial sounds, I had neglected to consider vowels. Some vowels are rounded though the altering of the shape of the lips, and I had neglected to examine if my injury had affected any vowels.