Current-gen systems won't run the games at 4K…

Switch (docked mode) – 1080p / 30 frames per second target

Switch (handheld mode) – 720p / 30 frames per second target

As for MGS1:

“arrives virtually unchanged, as this is an emulated version of the 1998 game, lacking widescreen display or up-ressing, which may come as a disappointment for players hoping to play MGS1 on their 4K TVs”.