Since the Source Gaming website is offline or something,
this site has their translation for now.
"…That said, if you were thinking that we’d just be dropping a bunch of newcomer trailers all the way up until release, you’d be sorely mistaken. We may have gone a little bit overboard up until now, so we’re going to slow our pace from here on out."
I'm still worried regarding Sakurai's statement on "revealing the design of every fighter before release". When combined with this, it does seem like there is very little left to be announced. Starting from E3, in about 3.5 months, counting echo fighters, we've gotten (including echoes) 8 fighters. Which translates to about 2.3 per month on average. (Not really counting the Inklings myself as it was moreso part of the smash announcement.)
...That being said. He specified newcomer
trailers, which isn't the same as fighter designs. As an example, Mewtwo's design was revealed before smash Wii U's launch (although after 3DS). I suppose this is a possibility to keep in mind. With development wrapping up within the next 2 or 3 weeks, there's a decent chance there are one or two fighters who didn't make the cut due to time constraints. I can imagine them being revealed like Mewtwo was in the 50-fact extravaganza. And while DLC isn't a guarantee... I'd be surprised if they didn't do it. It'd sell like hotcakes, after all. Especially since the switch has been such a success. Whether it's going to be standard DLC, only a Season Pass, or free updates like Splatoon, (or nothing,) only time may tell.
Of course, it's just a possibility. But I'd like to keep myself cautiously optimistic, so I like to entertain the idea.