If GPU rendering is required, Vantage fills that role. For Corona GPU, it would take a year of two of development, and bring all other development to a halt for that time period, and because GPU is not identical to CPU, it would not be "Corona, just GPU" which is what most people expect on making this request (even V-Ray GPU has differences from V-Ray CPU and the two are not one-to-one). For those reasons, there are no plans for Corona on GPU when it comes to rendering, sorry.
If GPU rendering is required, Vantage fills that role. For Corona GPU, it would take a year of two of development, and bring all other development to a halt for that time period, and because GPU is not identical to CPU, it would not be "Corona, just GPU" which is what most people expect on making this request (even V-Ray GPU has differences from V-Ray CPU and the two are not one-to-one). For those reasons, there are no plans for Corona on GPU when it comes to rendering, sorry.