If you have a brand new cart, play it on an already banned system, then play it on a brand new Switch...no, your brand new Switch will NOT be banned.
Now that that's answered, I'll answer a couple other questions you may have.
If someone dumped the cart (including the unique certificate) AND went online at the same time as you did with the physical cart...it's possible (not likely, but possible) that Nintendo would issue a cert ban, and the cart would not be usable for online play anymore. It is also technically possible that Nintendo could ban either/both Switches, but the chances of that are so low as to be nonexistent.
If someone dumped the cart (including the unique certificate) and made it available for others to download, and it appeared to Nintendo that a lot of people were using the exact same physical cart at the same time...there will definitely be a cert ban (affecting the cart only, not a console). As for a console ban, I'd say the console using the actual physical cart would not be banned. There has been one unconfirmed report of this happening, but I think it was just FUD/trolling. If Nintendo were banning consoles ONLY because it went online with the same cart as another...we'd be hearing a LOT more about it.
no no i already knew all of that stuff, i appreciate it though, the reason i ask is because i wanna play smash as much as possible and i dont want my banned switch spoiling the fun aka getting my other switch banned.