No. You can use either the software emulator or the ps2 hardware in a backward compatible ps3 to run iso on the hard drive. I don't know what the default is now, but you used to install the full rebug toolbox and use that to switch between them.
Original NTSC had EE+GS. Later NTSC+PAL had emulated EE but still had GS hardware.
The compatibility of the emulated EE with GS hardware is much closer to EE+GS hardware consoles than the emulated EE+GS.
Essentially EE is much easier to emulate than GS.