While it was generally expected that AMD will launch it next-gen graphics card in Q2 2015, which ends on June 30, AMD will apparently hold back the launch for second half of the year, most likely for Computex 2015, scheduled to start on June 2nd.
Answering a question from John Pitzer from Credit Suisse, AMD's CEO, Lisa Su said that Carrizo APU is a strong product and that the company will talk about graphics launches later this quarter. Su also noted that the company expect their products to take a strong position in the second half of the year, as well as to see the market gets stronger as well.
According to this statement, it appears that we will not see any AMD's next-gen GPUs launched before June but there is still hope that AMD could launch, or at least officially announce, its next-gen graphics cards in time for Computex 2015, a few weeks before Q3.