Various people (mostly Fatmanonice) have provided good and reasonable interpretations of what this quote might mean, "For example, I think pretty much the limit when it comes to creating characters for a Smash Bros. is about 20, counting those from older games. We remake them completely each time, after all, and the teams and personnel and specs are all different. But we all go beyond what the work calls for because we want to do our best to retain fans of each character."
However, I still find myself curious about one thing. Is there any chance that "counting those from older games" is mistranslated and means something closer to "when you take into consideration those from older games?" As in, when you consider they still have to remake all the old characters 20 is the absolute max amount of characters they can add. Just a thought.
That said, "limit" being hyperbole or being mistranslated seems more likely given what he says next. I rather hope it is the latter as "limit" does seem like an odd word to choose given that that number of total characters can obviously be surpassed. But there again, no one chooses the perfect words every time, and thus those who dissect what he says are doomed to be disappointed.
Anyway I'm not sure I learned much from this article, as the focal point seems to be how hard they work regardless of what exactly some of the individual sentences mean, and I already knew that. It's good to have it reiterated though, as it seemingly hasn't gotten through to some people.