It's believed that both products will hit the market in October 2020, after being announced at a press event in August or September.
It looks like AMD wants to have both high-end CPU/GPU platforms available on the same day so that people building new PCs can go all-AMD based on the performance of its next-generation product lineup. That would be very impressive for AMD if they can pull it off on the GPU side which might be true given the latest reports which suggest that AMD's RDNA 2 flagship GPUs are going to be super competitive in the high-end 4K department. There's still some time till Q3/Q4 2020 so we will be given more information along the way by AMD on its next-generation products but the info we have till now is mentioned below.Both products are expected to deliver relatively large performance gains. Hopefully, the launch won't be impacted by the current coronavirus pandemic.