Can I still find a purple flap bag anywhere? Will Chanel have another one?

Ebay is your only bet at this point. I spoke with Brendan at Chanel NY earlier this week and asked if purple would be returning. He was unsure until he receives more input for the fall. He added Chanel often brings back a color that was well received. (I, for one, sure hope so as I am hoping for a purple caviar either e/w or medium classic.)
 
i spoke with someone at chanel yesterday. they too said that they may do purple agian but not for at least another season since they usually wait a few seasons to repeat a color.