Meaningless PR as Black Friday has become a thing outside of the US, meaning for the time being, every BF will be the best ever as sales spread and become more commonplace. Once it either becomes the norm or retail has sense to axe it, we'll be able to compare BFs to see if they're better or not.
I would say since 5 years the black friday is important in Europe and it could have been last year for example but no PS4 slim at 299 euros/dollars...
I take the bet the PS4 will have the best holiday season since the launch and it is not a very risky one...
And It will be easier with PS4 Pro for hardcore gamer...