While FS2020 is a great looking "game" on PC, for console it will still be niche and most people will try it but i do not believe the majority of the mainstream will really care.
This a typical niche and hardcore game you want to play with a great setup and not with the controller.
So no...it's in no way a system seller.
First of all, the OP did not ask about system sellers. Secondly, looking at all the people I see literally begging for the console port every time Microsoft posts anything about it, you may be surprised by whether it's "niche" or not.
Here's a bit of history for you. Flight simulators haven't always been niche. 15-20 or so years ago they were among the most popular AAA games in the times of the earlier MSFS titles, Microsoft, and Lucasarts.
They became niche basically because Microprose overextended and died and Microsoft withdrew from the market, leaving the field to crap developers (at least from the point of view of being able to marketing their sims to a wider audience) like Laminar Research and Lockheed Martin, who have done zero to widen the community and pigeonholed the genre into a niche.
On the other hand, developers of other kinds of simulators (racing, train, farming, and so forth) stepped in and filled the gap with their own games for a less twitchy shooty kind of gameplay, which many people do want.
Microsoft Flight Simulator isn't "hardcore" at all. Its default aircraft are absolutely fine flown with a controller, and if you simply use it to "fly around and see places," which is a very viable kind of gameplay, even more so nowadays when many people can't fly around and see places, it's absolutely accessible. There's a reason why "sim" games have become more and more popular nowadays, including walking simulators. This can easily be used as a walking simulator, but in the sky.
You can underestimate it all you want, but you'll likely be proven wrong.
Does 2020 game ported in 2021 count?
Yes.
Made by Asobo the independent developer behind a Plague Tale. Not first party.
False. It's published by Microsoft and co-developed by Microsoft. It's first-party exactly like Bloodborne.