I fully expect the hardware reveal to come with new game reveals.
Z-A will likely be a Pokémon presents exclusive trailer. DK and Xenoblade won’t be used to show off hardware in a trailer that’s meant to appeal to the general audience on a newer and more powerful switch. Metroid is a good showcase of performance improvements but doesn’t appeal to those general audiences.
Realistically when they unveil this for the first time and the trailer spreads like wildfire they will likely want to sell consumers on new and popular titles that are completely new or unavailable on the switch (8/9th gen ports).
The first question the average switch owner who’s interested will ask is: what can this one play that my current switch can’t?