Nintendo has been seeing a sort of creative renaissance as of late, particularly regarding New IP. 2015 introduced Splatoon, the company's most successful original game in almost a decade. And just 2 years later, followed it up with ARMS, which while not as successful, still has a loyal following and is one of the best selling Fighting games this gen. If we continue to follow the bi-annual schedule, then Nintendo will introduce at least one new Mascot-driven IP in a similar vein to those 2 every other year, continuing in 2019. Shinya Takahashi has said that Nintendo has a lot of new and original ideas lined up for Switch, and that includes new mainstream character driven stuff like ARMS and Splatoon. A lot of projects Nintendo started around the time the Switch launched, will more than likely be ready beginning next year, so we should probably expect a new Splatoon/ARMS-like game that uses the Switch hardware in a unique way.

Personally, I would like to see something more single player driven this time.

I guess it depends on whether or not Town can be considered "mascot-driven". We'll see when we get more information on the game or when it comes out. But for the most part the reasoning is not that compelling. We shall see.

Town is from Game Freak, Not Nintendo. 

I agree. They seem much more inventive and ambitious with Switch than they were with 3DS and Wii U, so I'm also expecting one or two interesting new IPs from them next year. I mean, we already have Town from Game Freak, but I totally expect something new from Nintendo EPD as well. You know what would be cool? A new action/adventure game, I think they kind of need one or two of these.

I'd say we should expect a couple new ideas from EPD next year. Sure, one of them could be a Splatoon-esque mascot title. But expect at least another Labo-esque concept driven game from them or two as well. 

I would love when Nintendo would publish in 2019 a new IP with new characters. I know they make a lot of money with the current once but I wished they would sometimes take more risk and try to establish something totally new.

So they release 2 new IPs in the past 10 years and suddenly we have a bi-annual schedule?

From an advertising standpoint, 2019 seems too packed with Animal Crossing, a core Pokemon game, Luigi's Mansion 3, Marvel Ultimate Alliance 3 and Fire Emblem: Three Houses. That's a lot of ground to cover without mentioning a possible big Zelda game (like a mainline 2D one) for Nintendo's yearly Zelda title, Retro's game and everything else that has already been announced. If there's going to be a big, new, mascot-driven IP for core audiences from Nintendo, I think 2020 would be a better year to do it.

One thing Nintendo is not short of is mascots and it was notable that they didn't introduce “Labo Man” with Labo. My guess is that there will be no new mascot IP ... it even seems unlikely to me that there will be a new IP featuring an existing Mascot.

Nintendo has always produced new IP and one-offs. But Splatoon was signifigant in that it was their most successful one in almost a decade. I say we should see at least one new mainstream-character driven IP every other year since most games usually take around 2 years to make.