The argument being made is that the distinction between an FPGA and CPU is irrelevant to determine whether something is emulation.
An emulator accelerated by an FPGA is still an emulator and a CPU simulating a console at the circuit level is no different in accuracy than an FPGA doing the same thing.
The main difference is the experience, where the FPGA can offer an experience closer to the original than a CPU running an operating system can, especially for older consoles. Not because of a difference in emulation accuracy, but because the user experience is different.
That’s just building a unit to spec using an fpga instead of a chip fab. If it’s a 1-1 copy, emulation would not appear to be the correct term.
If I have a black box chip that takes in 3 bits and spits out 3 based on the input. If I make a bit perfect implement of it, but my chip has additional outputs that correspond to unused input, hence never used. Is it still considered emulation? It differs minimally in a negligible manner.
An emulator accelerated by an FPGA is still an emulator and a CPU simulating a console at the circuit level is no different in accuracy than an FPGA doing the same thing.
The main difference is the experience, where the FPGA can offer an experience closer to the original than a CPU running an operating system can, especially for older consoles. Not because of a difference in emulation accuracy, but because the user experience is different.