Sakurai finally released his second part of his famitsu column and gave a lot more information.
https://mobile.twitter.com/AllSourceGaming/status/1011992581461430273
One thing that has been debated over time, but yes Sakurai confirmed that Bandai Namco is indeed working on the game once again. This is a good thing seeing how it’s the same team that can improve on what they know and allow Sakurai to not make a new team from scratch.
He also said that he has to cooperate with EVERY publisher. Which can also include second party companies for their approval and what their characters’ limitations are, and with so many publishers he barely got them all aboard, which suggests why Sakurai stated it was a risk. This also explains why Sakurai stated that he does not think another Smash game with all previous fighters will happen again. Getting all the publishers to agree and allow their characters to be in Smash is such a big gamble.
Finally one interesting thing I noticed is that he said how Smash can lead a big impact to other games outside of it, meaning that Sakurai is well aware on how franchises getting exposure from Smash can benefit from it in the long run. I’m hoping this means that he might be interesting in adding content and even characters from lesser known IP’s like Golden Sun and Advance Wars. (One can dream).
EDIT: A couple of things I haven’t mentioned yet.
Sakurai also said that he gets requests and knows that people want him to work on other projects. However, Nintendo makes the call when Smash should get made, and priotizes it. This can also mean that Nintendo asked Sakurai to prepare for the new Smash game in late 2015 for the “NX”, which explains his first proposal and all that.
FINALLY, Sakurai explains that Smash is huge collaborative undertaking and is Nintendo “Primere” title. He also said that it’s natural for people to expect newcomers along with veterans, but implies that it takes a lot of man power to make it happen. This probably implies with what he said about Ultimate being the perfect (and only) time bring everyone back.