Well it is an interesting debate. I think the difference between what we today term 'retro' major appliances like fridges and so on, and a retro vacuum cleaner, is that the major appliances are fashionable for their vintage look, whereas a vacuum cleaner is fashionable for it's ultra model style. There is no accounting for fashion.
Take a mobile telephone and a landline telephone. As mentioned on another message strip, there is a certain demand it seems for a retro looking house telephone. I doubt that a mobile telephone -even if packed to the top with the latest features- would ever sell if it had a retro look about it. You could take that retro theme two ways when it comes to mobiles; you could have say a mobile telephone designed to look like those 1980's house-brick mobile telephones, thereby combining modern technology and old styling, like the retro fridges, or, like the retro washing machines and dishwashers which Smeg make, it could actually bear little to no resemblance at all of the actual vintage product which it is trying to be, and just has an overall vintage appearance.
I think the Maytag Satellite cleaner from a few years a go dipped it's toe in the retro waters so far as cleaning goes, and from what I recall it was not exactly going to out sell a Dyson. I realise of course that the Satellite had many a design issue which prevented it from being one of the better cleaners on sale at that time, but that would have only come to light after the purchase had been made and would have been mostly subjective anyway. From what I can establish, it did not have much of an appeal. I do wonder if this may have been due to the fact that a good deal of people who may be buying retro styled appliances would have been a little too young to recall the constellation first hand, whereas although the same could be said about telephones and major appliances, these products would have appeared many times as props in films, soap operas, and comedies, many of which have been repeated over and over again to the present day.
When all is said and done, I must say that my own opinion is that a Junior or Senior type vacuum cleaner on sale today would not sell well at all. Whether we like it or not, it seems to be the Dyson and those cleaners which look like a Dyson which are in the greatest demand.