It has to be a first, because it's incredibly rare to begin with that a game launches across three generations of consoles.

Some random thoughts:

More fodder for the thought experiment that Nintendo would have been better off by sticking with the Wii for ten years and then proceed to launch Switch instead of having the Wii U exist at all. Interest in Wii games remained for many, many years (besides Just Dance games, Mario Kart Wii shipped another 100k copies in the fiscal year ending March 2019), so all Nintendo would have had to do is to release the games that were made for Wii U on Wii in order to bridge the gap between 2013 and 2016. While third party support for the Wii would have been sparse during those years, it's not like the Wii U could boast with a healthy lineup. But considering how little the Wii U sold, an aging Wii would have more than matched that while being in a good financial condition.

But obviously, a much better alternative is the launch of a better console than what the Wii U was. A proper continuation of the Wii concept - therefore improved motion controllers instead of the non-motion controller the Wii U had - with a multitude of other natural evolutions would have been the way to go. But whatever, the mistakes have been made and are history, so an alternate history would have not resulted in the Switch console that is on the market now. "What if" scenarios lose a lot of their value once one remembers that there aren't exclusively positive consequences.

It has to be a first, because it's incredibly rare to begin with that a game launches across three generations of consoles.

Some random thoughts:

More fodder for the thought experiment that Nintendo would have been better off by sticking with the Wii for ten years and then proceed to launch Switch instead of having the Wii U exist at all. Interest in Wii games remained for many, many years (besides Just Dance games, Mario Kart Wii shipped another 100k copies in the fiscal year ending March 2019), so all Nintendo would have had to do is to release the games that were made for Wii U on Wii in order to bridge the gap between 2013 and 2016. While third party support for the Wii would have been sparse during those years, it's not like the Wii U could boast with a healthy lineup. But considering how little the Wii U sold, an aging Wii would have more than matched that while being in a good financial condition.

But obviously, a much better alternative is the launch of a better console than what the Wii U was. A proper continuation of the Wii concept - therefore improved motion controllers instead of the non-motion controller the Wii U had - with a multitude of other natural evolutions would have been the way to go. But whatever, the mistakes have been made and are history, so an alternate history would have not resulted in the Switch console that is on the market now. "What if" scenarios lose a lot of their value once one remembers that there aren't exclusively positive consequences.

Not as good as E3 2014, but better than any of their other E3 shows since then.

Still no Bayonetta 3 after a year and a half of waiting since its announcement really sucked, (seriously, don't fucking reveal a game if you don't plan to actually show it for years on end) but Witcher 3, footage of the next mainline Zelda, and tons of awesome-looking gameplay of Luigi's Mansion 3 and Yooka Laylee & the Impossible Lair made it worthwhile.

Plus it was a relief for Spyro Reignited to finally be confirmed for Switch; not because I'll necessarily buy it but because the annoying back-and-forth of leaks and secrecy over whether or not it would come were driving me up the fucking wall.

And even as someone with no interest in Smash, seeing Banjo & Kazooie back on Nintendo made me feel warm and fuzzy.

I think they didnt show Bayo 3 because Astral Chain was there. Even though they will have different release dates maybe they think they will be competing against each other.

Perhaps at the game awards.