Well I think he was talking about the actual game itself, not the impact it has on the industry. That's like saying that no mario game has eclipsed the original because the original had the most impact on the gaming industry or more broadly on culture itself. Fact is that in terms of the actual game, unless Nintendo somehow screws it up, BotW2 should definitely surpass the original in many areas because they can see what improvements people want and implement the ones they see fit. Only real question is will it feel stale cuz its in the same world, or will everything else about the game be so new and cool that people don't mind playing a new adventure in the same place all over again.
He specifically pointed to sales.
Also, I'd also disagree with your Mario comment. Super Mario Bros 3 eclipsed the original Super Mario Bros in many regards including culturally, critically, and commercially (given it remained the highest selling unbundled video game for years).
Yeah, he said it won't surpass the original's sales. What's your point? He was talking about the game itself being surpassed in every way.
He was saying gameplay will be better in every way, but it won't sell as much. He was not saying it will revolutionize zelda or open world games like the original or have the cultural impact of the original. He's talking about will the game improve in a lot of areas and likely be a better game overall: yes. But despite that it won't sell as well. Precisely because it won't have the cultural impact of the original because its a sequel just trying to do one more round of BotW rather than some brand new innovative thing. Like how Galaxy 2 was better than Galaxy but didn't sell as well because Galaxy was this crazy new take on Mario while Galaxy 2 was just doing the same thing but better, so Galaxy 2 wasn't a new type of Mario that you just HAD to check out, cuz it'd already been done. BotW is pretty much a straight comparison to Galaxy. BotW2 may surprise us all and sell even more than the original, but I doubt it.
And you're being very nitpicky with the SMB comment and missed the whole point. I wasn't trying to start an argument about which Mario game has had the largest cultural impact or saying better games later on can't have as much cultural impact. I was making the point that the guy was making a comparison about the predicted quality of the games (BotW2 vs BotW) and not saying BotW2 will have a larger cultural impact. Your responded to him arguing it won't have as big a cultural impact and whatnot when he said absolutely nothing about that, so your comment to him didn't make sense because you're arguing against something he didn't even mention.
He was talking about the game itself, not its impact in society. SMB vs SMB3 has nothing to do with any of this. But since you bring it up, SMB3 was bigger culturally because it revolutionized Mario (notice how Mario 2 didn't have a big cultural impact and hell wasn't even released in the west because it was just a more of the same sequel). BotW2 won't revolutionze Zelda, because the incredible open world game revolution for Zelda just took place and by all accounts BotW2 is just expected to be the same type of experience, hell even the same map, but just with a load of new content and lessons learned so likely Nintendo will improve many facets of the original.