They mentioned somewhere that they could not designate the actual area increase since it is part of the synthesized digital area. The area increase to include the RISC-V cores was negligible, apparently.
I wonder if without the RISC-V cores the design was pad limited i.e. it had due area that wasn't used. So, they put in the RISC-V cores for no die cost. There will be some cost to test the RISC-V cores.
