So why is it 200 kts? Any technical reasons for that?
Flaps 2 speed limit.
If the Slats are at position 0, selecting Flaps 1 does not give you any config change (due Slats jammed). When you select Flaps 2 there is a big pitch & trim change required to maintain level flight. (You can often feel the aircraft struggle to maintain 1g in Normal Law when going from Slats 1 to F2). Don't be surprised if you trigger a momentary "Stall Stall" warning. It's due to the +ve delta g (which you won't feel in the sim) as the flaps run out and being closer to the stall due no slats. As you reduce the pitch attitude, you'll reduce the g and the stall warning will cease.
ECAM has the conditional line:
"WHEN SPD 200 KT (displayed when slats are retracted):
L/G ...... GRVTY EXTN"
whereas the QRH does not mention the condition (to keep it simple).
When you are manually flying in Direct Law, you will feel the forces required better (when only the Flaps run from 0 to position 2), be able to move the Stab Trim faster than the automatics can and balance the required manual thrust.
We used to call it "flying the aircraft" in the old days.