Your conclusion that BotW must sell 2.5 times that of Zelda on NES is completely nonsensical and is not backed up by your arguments. Your only numerical evidence for this is US population growth and Switch's worldwide appeal. The US population has only grown by a factor of 1.35 since 1986, and population growth would actually help Odyssey to a greater extent than it would help BotW because 3D Mario is more popular in the US than 3D Zelda. As for worldwide appeal, even if Switch becomes just as popular in Europe as it is in North America, that wouldn't let it reach 16.5 million.

4 million (Ocarina of Time, NA) * 1.35 (US population growth) * 2 (Europe turns into NA) + 1.7 million (Zelda NES, JP) + 1 million (Optimistic RoW) = 13.5 million

Of course, it doesn't even matter just how well Breath of the Wild does, because Odyssey is going to do better. In Japan, Odyssey is 700k ahead of BotW, which is an even greater lead than what Odyssey has in the US. The original Zelda on NES is still the best-selling Zelda game in Japan, and Odyssey is already ahead of that. You list Ocarina of Time as a previous Zelda game to have this kind of impact, but Super Mario 64 was still more popular than Ocarina of Time in every region. The US is BotW's best region, and Amazon shows that Odyssey is consistently outselling it there.

Finally, that Odyssey bundle sold nowhere near 3 million. If you look at the US Amazon charts, it was behind both of the $300 bundles in October, and then completely dropped out of the top 100 in November, never to return. It didn't even reach one third of Switch sales during its best month, so it is baffling that you think it accounted for more than 40% of Switch sales over the entire holiday quarter.

I say zelda has no chance to beat Mario. More casuals and people overall know the character Mario over Link. Mario is just a juggernaut

Both games will be the highest selling in their category (Legend of Zelda and 3D Mario). While Zelda is certainly the more groundbreaking of the two - and I would even argue the more widely appealing, it is up against the latest flagship title of the best selling and most well known video game character in history.

If i were to tell you BotW is outselling SMO in "Japan"  now weekly despite the former being 1year old would you believe me? :P

Considering Zelda was released before Mario and has already been passed by it, it is unlikely that will happen

The only chance BotW outsell Mario Od is if there's no more Zelda games on the switch and that Mario Od 2 releases

Im joking, well i mean its obv smo will sell more. Its only weird that zelda in Japan is outselling Mario weekly now

Zelda will not beat Mario long term at the end of the day. you will see

Wasn't the pack-in digital anyway? Which means those numbers aren't even tracked here? So Odyssey is beating BOTW even without the pack-in.

Very unlikely

3D World did really well on the Wii U. Mario Odyssey will have longer and better legs than BotW