Indeed, and as has been shown with i-phones and personal computers now since long, people don't mind paying MORE right now, rather than wait and spend less later. They want it NOW, even if they could get it much cheaper next year.
So the myth of postponing consumption because of price decrease is simply that: a myth. People don't postpone consumption because of projected or real price decrease of the *same* item next year. Nevertheless, this basic assumption needs to be made to "prove" decrease in consumption due to deflation.
Actually, what happens is that historically, one finds *correlations* and one assigns cause and effect the other way around. Deflation can be a consequence of consumption decrease. It is not its origin.
Like having a Rolex on one's arm is a consequence of being rich, and not the origin of being rich. It is not because you put a Rolex on your wrist that you suddenly became rich. Nevertheless, there's a strong correlation between people being rich and people wearing Rolex.