I think that is a reasonable inference given that CP3 and Stewart bring a similar skill set to the game. If Candace were say 34 and in the waning stages of her career, you could almost justify this decision. But Candace is still a prime time performer with 8 years of professional and international experience. There is no way Stewart--player fresh out of college--is at CP3's level.
This dropping Michael Jordan to make room for the 18 year old Kobe.
I don't think that having Stewart on the team is that unusual. They did the same thing for Candace when she was fresh out of college, and it's all but written in the stars that Stewart will be a star in the WNBA.
The problem is that they left the best PF off the team in favor of the rookie, a player in the twilight of her career, and a PF who is surpassed by Parker in all aspects of the game. It's that last one that is a headscratcher.
If any player should have been left off the team to make room for Stewart and Catchings, it should have been Tina Charles. The fact that she was a prized pupil for Geno at UConn and that she's on the Olympic team over Candace is not a coincidence.