I don't see XCX as much of a system seller tbh. However you are right, Splatoon could still drive some decent hardware sales this Christmas as that was a pretty big hitter and with Nintendo's market more being driven by parents buying systems for their kids, if their friends had Splatoon they may well have put the Wii U on their wishlist this year.
The issue I have however with "well past hits will also drive sales" is it makes it sound like the Vita has no software at all that people may want from it's legacy catalogue.
Persona 4: Golden sales could be driven by Dancing All Night hitting, but more so from the big interest in Persona 5 that is starting to pick up.
Uncharted: Golden Abyss could also gain more interest from first the Uncharted Collection hitting, then also Uncharted 4 next year.
There are also a lot of curio titles which could tempt people over once the system has a price cut (Price point isn't only a potential ammunition for Wii U at this point).