Gonna disagree and say we are only a couple years away IMO.
Not sure if you guys know this or not, but Furakawa had an investors meeting and was asked about next gen consoles and pressed on the issue when he tried to avoid it. His response was, paraphrasing of course, that 'they are in the planning stages for announcement and release' which, if that doesn't quite click right away, means they are in the planning stages for ANNOUNCING and RELEASING their next gen console and NOT in the planning stages of DESIGNING the next gen console.
In other words, Furakawa might as well have said 'it's a matter of when, not if' which to me means that, much like I already thought, the next gen Switch with 4K and whatnot always was a thing but got leaked way earlier than Nintendo would have liked. They already planned on having a slight update to the Switch with the OLED and everyone did that silly thing again where they disregard good information because it didn't pan out within their own sense of timely expectations.
When we first heard rumblings about it and then the OLED happened, I knew immediately that Nintendo was using this opportunity to convince people there was nothing the works so that they would be more likely to buy the OLED and throw people off their trail. It's mostly worked as well, but I feel like anyone can look at Bayo 3 and 3D Kirby and see that the Switch can barely handle these new games coming out. Nintendo is moving up in software, it's time for the hardware to keep up.
I'm going to toss out some of the other reasons I didn't mention in a previous post that 'Everyone Is Still Here!' is going to be a thing. This meeting with Furakawa confirming there is a next gen console in the works is a big part of it, but I already knew there was one: all this does is let is know they are ready to roll this thing out in the next couple years, so we have a timeframe between 1-3 years left before this happens.
Sakurai's own language in his most recent Famitsu is a big deal. Now, I will insist this here since I think people will make dumb assumptions if I don't, but I'm not saying we have proof Sakurai is already working on a new Smash title. We have no way of knowing that for sure at this point, and I wouldn't say anything otherwise. What I AM saying is that the language Sakurai used is his generic 'this is the last Smash for now and nothing is in the works at the moment' that he has used multiple times in his career. This is very safe and generic language and, more importantly, it's very similar to what he said at the end of Smash 4...you know, when he was already working on Ultimate shortly after? Like, in the planning stages at the very least in early 2016? In other words, Sakurai has done this old dog and pony show before, and the last time he did it he actually was working on Smash already. Thus, he COULD be in the planning stages of another title for a next gen console already and no one would ever be the wiser...well, MOST wouldn't.
What is also important is his language about not thinking anyone can replace what he brings to Smash, which matches up to his interviews with Harada, and his talk about not wanting to disappoint fans and his worry about making cuts. This first part is proof that Sakurai will be at the helm of Smash until he physically cannot do it anymore, so no, he's not retiring...though you may have gotten that already after it hasn't happened since Brawl. The second portion is proof enough TO ME that we will get a glorified port of Ultimate on a next gen console in a couple years, and it will have every single character that has been in the game all the way up to and including Sora. Of course it will have a number of QoL improvements and new features and more characters, but I think it will be largely the same...though I would be more than pleased to be wrong and outside of the roster it gets many massive changes.
One last thing to mention here is that Furakawa is the gamer president where as Kimishima was the businessman president. Sakurai wasn't given the option to delay Ultimate because it was only a couple months from coming out the door by the time Furakawa took charge. However, now Sakurai gets to make a game with a president that seems to be kinder and more understanding and more giving of creative freedom, which could easily mean that Sakurai gets more power back in regards to character choices as well as how DLC is done. Additionally, Furakawa believes that the SNES-Gamecube Era of Nintendo are the best Nintendo has ever been, which gives a big boost to the chances that a lot of these missing characters could and likely will show up in the base game of a Ultimate: Definitive Edition.
I think
pupNapoleon
gets to have some credit as he was the one who seemed to really bring back this topic around Sora's announcement, though I most definitely talked about this long before that and was basically asked to turn myself in to the psyche ward. I am very much convinced this is the route they will take, it's just perfectly set up.