It's definitely not a saloon.
This. It's a hatchback.
The definitions are pretty clear:
Hatchback: 5 doors; the boot is part of the main cabin (may have a parcel shelf or other temporary barrier, but still fully accessible from the cabin).
Estate: 5 doors; a hatchback with a (near) vertical tailgate. Floor area/shape in the boot is often the same as the hatchback version of the same car, but the vertical tailgate gives more load space (OK, maybe there's some ambiguity as to at which point "near vertical" delineates the difference between hatchback and estate, but if we're talking about the ID.7, then the tailgate is about as vertical as your mum after 18 pints of vodka.)
Saloon: 4 doors, plus a completely separate luggage compartment (sometimes with a small hatch in the middle to allow longer loads - e.g. skis)
SUV: higher ground clearance, rugged, 4 wheel drive and off-roading capabilities
Crossover: looks like an SUV, but is basically just a hatchback on stilts. Off-roading capabilities limited to parking on the kerb across random peoples' driveways on the school run.
Yes there are hatchbacks which look like saloons, think Mondeos/Octavia/Superb etc. (which do also come in saloon variants), but if you can climb through the boot to access the cabin, then it's still a hatchback.