And Pokemon!!!

This ain't your average spin-off by any means. They just called it that to get people who were freaking out thinking this was Gen 8 to call down. That's why they said right afterwards that the true Gen 8 was coming out next year. But, even though this isn't Gen 8, it functions and plays just like a mainline game for the most part, with the only difference being the Pokemon Go mechanics. It's essentially an overgrown, stealthily disguised, Pokemon Yellow Remake with Pokemon Go elements. And its pre-order sales have been on the level of a mainline entry.
This is going to sell huge numbers, possibly even more than Smash Bros. and it is going to sell a lot of systems.

enjoy it while it lasts Sony

now you haven't let crossplay happen in Fortnite, literally no one will ever buy your console again and xbox is about to surge into the lead

Im so disappointed in you Shadow, they have confirmed on numerous occasions now that it is a mainline title, not a spinoff.

I think pokemon go might hurt the franchise. i'm sure most people buying are gonna think its a true mainline pokemon for the core fanbase, when the game is average, and i'm expecting low review scores, it ill kill the hype the pokemon 2019 big time to the people that don't follow games before release.

Hear, hear.

I've sold my PS4 and will be picking up an X1 and a Switch in December. Must punish such behaviour.

Ya because the core pokemon fanbase or core gamers in general dont look up videos/previews/impressions of games before purshasing them......

I dont think you even believe half the things you say.

Yep

In the conference, the games are explicitly referred to as "mainline" several times.

Timestamps of "mainline" references:

3:10

And the second, is the new main series Pokemon RPG for the Nintendo switch

17:25

I'm happy to announce the newest titles in the mainline series of Pokemon RPGs: Pokemon: Let's Go Pikachu and Pokemon: Let's Go Eevee

20:32

I wanted to bring the fun of this more intuitive as well as widely accepted and popular Pokemon catching gameplay right back into the Pokemon main series RPGs, so I decided to work on Pokemon let's go Pikachu/Eevee as the director.

28:29

We decided to add this local, simultaneous two player gameplay for the first time in a mainline Pokemon rpg

31:22

These first main series Pokemon RPGs on Nintendo switch

40:14

We're also hard at work on another all new core series Pokemon rpg on the Nintendo switch

Except for the fact that The Pokemon Company and Nintendo made it very clear that Let's Go is not Gen 8 and that the true mainline Pokemon game for the core fanbase, the real Gen 8, is in development and planned to release in next year. And if anyone paid even the slightest attention, they would know that.
As for killing hype for Gen 8 in 2019?
<insert Titus laugh here>

believe it or not, most people don't, especially in huge franchises.