It's an interesting question - mainly because it's elicited a bunch of responses. My answer would be three fold. First, no team is going to make a trade not knowing which position in the draft they are likely to get. Obviously there will be 4 teams wanting the top 3 spots since Griner, EDD, and Skylar should be the first 3 taken. I have no idea at this point who #4 will be, but Atlanta would be nuts to trade for the #4 pick.
Secondly, why would Atlanta want to trade Angel? She's a superstar who was one of the key players on the US national team and was often 1st or 2nd off the bench. At this point, the only player of the big 3 i'd even consider trading Angel for would be Griner. Part of what makes Angel great is her defense, which is light years better than even any potential EDD has.
Third, Harding is their 1 and Price is their 2. Both are terrific and average over 9 PPG. They also have Hayes who has shown that she's a terrific guard as well. I'm not sure where Skylar would fit in, and certainly trading Angel for her would be a huge downgrade, and give them a player who plays a position they already have 3 really good players to cover.