If it is very close to the Trafic, the logic would be to call it SpaceClass (like the current Trafic with seats), or Passenger (like the 2nd gen).
Another option would be to name it "Grand Espace", which would be weird as usualy the Espace and Grand Espace were very closely linked, but why not.
A third option would be to rename the SUV "Grand Austral", what it is anyway.
And lastly, if they do a MPV on this platform but with a different body than the Trafic (which I would prefer, I think the problem of the ID Buzz is that it is too tall, a MPV should be closer to 1.75m instead of 1.90 and can afford a more aerodynamic body than a van derivative), the Espace SUV could be old enough when the MPV is ready to be replaced anyway