Did you read this article? Because almost all of it is wrong.
What the actual reddit post said is that only counterfeited game cards would get banned if their unique card identifier didn't match the game contents. Systems and accounts would get banned by having mismatched install tickets (digital rights licensing) from their system and account IDs. It's been VERY EASY in the past to install digital tickets on Nintendo systems, and nearly all of their piracy happens by people adding tickets to their system that give them access to the game download via the shop. But there are also flashcarts and counterfeit cartridges on the market that would face a ban, and those are the carts you're referring to. Nobody is overwriting official Nintendo cartridges with other games, and the CFW doesn't write anything to the physical media. Also, Yuzu CFW for Switch has been around since February and operates on 3.0 FW, and SX OS was released in May. Basically, the people who are getting banned are stupid and deserve it. Again, it's not the cartridges. There's no way it could be, unless you are buying known counterfeits where the card ID doesn't match the game.
In yet another episode of why Nintendo will eventually go under. . .
Microsoft and Sony have been banning systems and accounts for a decade whenever people go online with hacked media. But while people were getting banned for hacking CoD, I was loading pirated games on my hacked Wii and playing them online perfectly fine. Wii, Wii U, and 3DS hacking methods now involve pre-bios loading of emulated systems for obfuscation and console anonymity, then you install your games to that. I use my hacked 3DS online just about every day, and on the off-chance that my system is banned/bricked, I'll just make a new emunand. The idea of generating installation tickets for digital games based on both the device ID and the account ID would flag any emunand I create and ban them, unless I was able to reproduce the algorithm. It's a great solution and will definitely impede the progress of piracy. This is going to deter piracy to an extent that sales increase, if anything.