It fires up and revs to 2000 RPM
I believe this is not untypical for a car with a fly-by-wire throttle. I think what is happening is that the ECU transitions from the cranking map to the cold start map to start the engine, then it looks for a valid Pedal Site signal from the throttle to see what the torque demand is. When it gets a signal it then knows what the target revs are (idle in this case) and lets the revs drop down to the desired level.
Why 2k revs? because in the absence of a correct throttle signal this will give you enough revs to drive the car, just like it was in limp mode. The GM Ecotec engine in my 4/4 does the same thing, runs up to just over 2k rpm on startup and then drops down. Doesn't do it when the engine is hot, presumably because the cold start map isn't necessary and it transitions straight to the normal running map.
