Personally I'm not 100% sure how to define what 'Granny Panties / Undies' are. Are we talking about the full on 'Bridget Jones' or just underwear which covers most of your bum.
I'm not sure if I've seen more ladies wear 'bigger' underwear on MFC, or if they seem to be coming back into fashion, but with most fashion, these things come and go. Although, seeing a few recent TV adverts for Women's products, the model's are wearing larger briefs. I'm not sure if this has been the norm, or something new I've just noticed, I don't pay too much attention to adverts, but it seems to me the larger underwear is perhaps a bit more prominent these days.
Personally, seeing the plethora of women's underwear on MFC is hugely fascinating. Everyone has a slight variation, either through style, colour or type, and that's wonderful to see. Sexy undies don't have to be tiny or have holes in the crotch, or essentially cut you in half.
Personally I quite like the larger undies, as seen by that 'Lost in Translation' post above. I suppose with most things it's variation, whether it's either the comfy black undies, or the bright pink glittery ones you keep for best, seeing the huge contrast in ladies underwear is a wonderful and enthralling thing.