Someone who knows Squamish better than me will be better placed to say, but it sounds like this might be at the Grand Wall Boulders? https://discord.com/channels/1032995878996287620/1265217121328304211/1516144764196622388
Seems to be a pattern that elite climbers don't necessarily know about specific crags within areas, so they usually use landmarks or famous boulders as references. Don't think his mention of the Grand Wall had any relation to Grand Wall Boulders specifically.