It is up to the installer to decide if it will be a separately derived system or not.
If you switch the neutral and put a bonding jumper at the generator it will be an SDS.
If you do not switch the neutral and do not install a bonding jumper at the generator than it will not be an SDS.
Both ways have advantages and disadvantages.
Primarily non-SDS is cheaper, SDS works better with GFP mains.
