I don't think that it's generally considered to be unimportant. Discussions about GAI tend to arise with respect to meeting threshold scores for entry to a gifted program. Some other parents seem to want primarily to present their children to best effect (for want of a better term), but to me this seems minimal by comparison with the desire for access to services.
Informationally, the GAI of course doesn't add anything when the subtest scores are available; one can then see the lower working memory and processing speed coupled with higher scores in other areas that would make the GAI useful to calculate. One thus might fairly conclude that presentation of a GAI with the subtest scores implies a tendency to disregard low working memory as unimportant, except that some testers will generate the GAI as a matter of course when indicated, and a parent might just be reporting the information they were given.
I agree with ColinsMum that aids as simple as pencil and paper, plus good organizational skills, can compensate a great deal for a relatively weak working memory. I still think the effects of a relatively weak working memory will be felt some of the time-- in my opinion a person will tend to have fewer or at least less deep or complex flashes of insight under those conditions. Basically, anything where it's useful to hold many things at once in one's head would be impacted. I know this is not a revelation.
