Well it would seem to me that unless you have a real injury, "other commitments and rest requirements" is pretty unacceptable.
"If the top two seeds, Minnesota and Los Angeles, advance to the Finals, as they did last year, that will mean nine listed players won't be able to participate. Right now, there is no plan to add any others to this camp, but USA Basketball may consider it".
I could see players being unable to make it because they are in the finals, but to announce now speaks volumes about their commitment to USA Basketball.