Sorry if I came across as too harsh.
Being totally honest, I can't imagine a scenario where arguing that one product (potentially) sells more than another because it's older or newer makes any practical difference in real life, since both are still being sold in some shape or form, that's all that matters to them and it's why I'm strongly against the point you made against emulating current gen consoles.
This is intellectually dishonest. Those are not mutually exclusive things, one of the many reasons I advocate against IPs is because many of the laws around it actively go against the very concept of digital preservation, mainly due to how fucking old they are, and even when there's some exemption to it there is almost always a loophole that favors the IP holder (like circumventing encrypted software). There are many other valid reasons to be against IP in general, like the patent industry and the negative effects it has to the access of medicine. Saying that someone doesn't care about preservation just because they are in favor of piracy isn't as strong an argument as you think.
Newer emulators are more and more complex to develop, many of them are open source collaborations. Unless you are being backed by a corporation like Nintendo's internal team making their commercial emulators, gatekeeping them is just unrealistic.
How much would Mario Bros for the NES make Nintendo today? Being part of the NES, a small part, I would argue little. Noones gonna go and buy a Switch, for Mario Bros Nes alone.
Mario Oddysey itself made about 1.8 billion on sales. It helped selling tons of consoles added to that.
Nintendo has claimed that for example Zelda was pirated 1 million times. A number that could be very well true, seeing the switch pirate reddit has almost 300k users. That's a loss of 50 million dollar, without even counting extra hardware sales. Surely, not everyone would have ended up buying the game, but even at a fraction, multiplied over several big releases, the numbers add up.
Offcourse, a lot of those aren't for emulation, but also hacked switches. But it's just to show that there is a huge difference in logic, for an old release vs one that's new.
The whole IP debate is another tale. But just want to pick on "it goes against digital preservation". Circling back to before: it's not a right. I would love to have older games re-released, like the old WWF/WCW games of the AKI times, and I know it can't because of IP's, but replaying what has been isn't a right. It's sad, but it's how it is.
It's the same for emulation, it's not a basic right. It's good for those wanting to create something, but not at all cost. You can develop in a team, without releasing it to the entire world.
When Switch games came out, new, and wouldn't work with an emulator, a patch was created in days or weeks. That's pure and simply supporting piracy.
Emulators have been protected for a long time, but it takes only one lawsuit to destroy them and make them illegal. And at this rate, it will happen.
So anyone truly caring about preservation, should discourage any potential for piracy. Why take risks?