Oh yeah? In that case the press that I read was wrong as it stated that she was present but not participating.
I think you are remembering the gathering out West either last spring or maybe longer ago when she was injured and couldn't participate. I think Augustus or Whalen was also on the sidelines and maybe another player as well - they were all present and active during the practice, just not on the court.
I believe Candace has always made camps and competitions when she has been healthy - I am sure she missed time before/after her pregnancy, but if she has been healthy she has been participating. So I think that story line has no legs.
The only person who I can remember 'begging off' a USA team when generally healthy was Cappy (and thanks Nan for finding those stories.) In her case it had a disastrous effect on her future with the team, not for politics, but because with a new coach and a new system two other players were added to the team - Angel and Whalen - and did really well providing the offensive punch, more disruptive defense, and better PG skills, and when the next team was pulled together they had passed her in knowledge of the system and particular skills needed for the team. And Pondexter wasn't a fixture for the NT - 2008 was her first team, she was a reserve who played well but her stats were just average - 9th on the team in scoring, with 17 assists and 5 steals. In her absence in 2010 and playing off the bench Angel was second in scoring with 9 assists and 24 steals and Whalen scored about the same with 14 assists and 12 steals, and they both rebounded better. In effect the team had moved on - had Cappy been available in 2010 then one of the two would not have made team, and in 2012 they would have had to play well enough in trials to supplant her as opposed to the other way around.
To some degree I think Parker falls into the same category - Stewart was on the 2014 team because both EDD and Parker were unavailable. Having gotten into the team and with a future upside and a position as the 'rookie' she was not going to be displaced. The real decision came down to EDD, Catchings, and Parker - the three players unavailable in 2014. Catchings like Bird and Taurasi was not going to be displaced and is a team captain. So the final throw came down to the reigning WNBA POY and the former two time WNBA POY. Neither are stellar defensively, and offensively they are both great but slightly different - EDD is better in the midrange to the arc while Candace is stronger from 15 feet in - both great players. Pick-em.