These are stronger arguments than what memoryman came up with lol. I'll quickly go through these with points against them.
While usually the websites don't usually don't have perfect layouts where everything fits in perfectly (Smash 4's website especially) they are clearly attempting to do so with the stage page already (with everything centred and nice looking). While you could use that point to argue in favour of 103 stages (as the page already looks finalised, at least on the desktop site), the fact that there are exactly five gaps in the collage just comes out as stronger evidence because:
- It matches up exactly with CoroCoro's stage number.
- The number perfectly fits the current stage select screen (especially when considering the DLC button).
Isn't it a strange coincidence that both the SSS and website seem to be designed to fit the same amount of stages, especially when you consider that the random and DLC buttons would be missing from the website version?
Again, I think the number is too specific and works too well with the evidence we have for it to be a typo or mistake.
Total ≠ final. Also, doesn't specifically pointing out the "we have exactly 100" line go against the first argument that Smash never has perfect numbers? I'm sure Sakurai just found it neat that he was able to say there were 100 stages, there isn't really any other reason for removing the Smash series stages from the total. I doubt they decided on 100 + 3 stages specifically at the start of development.