The U.S. could choose to have Alysa do both — especially if Nathan opts to do just the short (since men’s singles is first up after the team event).
I feel like the US will choose Alysa to do both since she's so much more consistent than every other US lady. Yes, the stakes are significantly lower in the free program since whichever US lady chosen will most likely be in a solid third place, behind the Russian lady and the Japanese lady, but ahead of the Canadian lady and the Chinese lady. Alysa has the chance to place ahead of the Japanese lady, which I would say none of the other American ladies have a chance of doing.
Further, since Karen and Amber are both inconsistent, there is a significant possibility that they don't skate well, and place below Maddie Schizas (Canada) in the free program, Maddie has scored ~124 at both of her major international events this season, whereas Karen and Amber have each had a bomb and a stellar program, with Karen scoring 114 twice and 135 once, while Amber has scored 123 and 133. Karen can certainly place below Maddie Schizas in the free program, while Amber also has that possibility. To avoid that risk, Alysa should do both programs, especially since Alysa is a very outside shot for an individual medal, and there's a lot of time between when the team events and when the women's competition starts, for her to fully recover her stamina.
The men's competition starts I think just a few days after the team competition concludes, so I think there's no way Nathan does both segments, and either Jason or Vincent would fill in very well for the free program (probably Vincent since he has the higher technical ceiling). The obvious choice would be to split dance, since H/D and C/B are both incredibly strong competitors (certainly more competitive in dance than any of the US ladies are), and there's also less time between the end of the team event and the dance event, so neither team will be too exhausted for the main individual competition. It's just a much safer play to have Alysa do both segments, maximize points, and split dance.