Was the change in spelling from "cw" to "qu" in English associated with any difference in pronunciation?

Question

I always thought that "cw" in Old English represented /kw/, and the same for modern English "qu", and that the change from one to the other was purely orthographic, since the "qu" digraph was more familiar to Anglo-Norman scribes. But on an English Stack Exchange question, I came across the following comment with 6 upvotes:

You should really explain that the second group are almost entirely due to the Normans being unable to pronounce the Celtic/Anglo-Saxon "cw" and so substituting the nearest Latin equivalent, "qu".

also

"qu" was not pronounced exactly as /kw/ by the Normans, any more than it is so by modern Frenchmen: English took several hundred years to smooth the two together. There is an interesting question about exactly which phonemes the Normans distinguished that the Saxons did not and vice versa

What does this mean? In modern French, I know that "qu" is generally pronounced as a simple /k/. But that doesn't exactly seem to be what this is saying. Does anyone know if there is evidence for some systematic distinction between a "Celtic/Anglo-Saxon 'cw'" and a Latinate "qu" during the relevant time period? If they were distinct, what was the phonetic difference?

Answer 1

Anglo-Norman French (or Anglo-Norman) was a dialect of Old French that died out as a spoken language by the beginning of the 13th century. It was used by by the ruling elite, which constituted no more than 2-5% of the total population (Upward and Davidson 2011).

Norman Blake writes that English monasteries started receiving a lot of monks trained in France who started copying OE texts applying spelling practices found in the languages they were familiar with (Old French and Latin?). He argues that these changes do not necessarily indicate any phonetic changes (Blake 1992: 10).

Obviously, as David Crystal puts it, "the incomers had no interest in preserving the distinctive Anglo-Saxon letters" (Crystal 2012: 60). Moreover, the West-Saxon educated elite that was responsible for developing and maintaining the WS standard gradually lost power and by the end of the 12th century their spelling practices were abandoned (Blake 1992).

The letter Q was rarely used in OE; thus, [kw] was usually spelled cƿ (c followed by wynn). So called Norman scribes started to latinize it by replacing it with "qu" in English words:

OE cwen => eME cuen, cwen, quen, quuen, qween, kuen etc.

Upward and Davidson argue that by the 14th century "spellings with QU had become the norm" (p. 149). For more details, see http://www.historyofenglishspelling.info/

Trask 2010 basically says the same thing, perhaps in a more understandable way:

An important addition. Cecily Clark (Clark 1992) argues it is incorrect to ascribe such changes solely to "widespread scribal ignorance of the English language."