Understanding what was possible with SXOS is irrelevant to what actually happened with SXOS. Nintendo didn't sit back and just ban cert/uids. They took a proactive approach that disabled SXOS from progressing. Banning certs wasn't their top priority. Now, people don't go online with SXOS unless they are trying to get banned. It's true that there was incentive to grab certs/uids, but the system bans were more prevalent and avoiding those were a greater focus to pirates at large. It's even likely that they banned systems before banning certs, but used cert ID'ing as a method to do so.
MIG offers non-CFW options for piracy play online. If this cannot be knocked down with cart detection techniques of Lotus3, then it is reasonable to assume that certs/uid management is going to be the main focus on both sides. It is a clear escalation. I have no reason to believe that SXOS did this the same way that MIG promises to do so. With SXOS, most users relied on one person to dump a cart, and to use that cart (along with its certs/uids). With MIG, everyone is incentivized to find their own certs/uids anyway possible. To suggest that these are the same thing is disengenious.
Here's the thing. We are both trying to predict the future based on the past. The difference between your approach and mine is that I am accounting for the fact that MIG will incentivize cert/uid ripping in a way that SXOS never did, and the potential reaction poses additional risk to Nintendo's image. You don't have to believe me, and I don't have to believe you. It's possible that Nintendo will do what you say they will. I am arguing that if they want to protect their brand, they will be more diplomatic than to sacrifice 1,2, or more potential innocents for every 1 "terrorist". If they cannot stop MIG at a hardware level, then escalating a cert war will only continue until people don't feel safe buying used Switch games.