Average wait time is 12 weeks from order to delivery, APART from during summer when the factory closes for Aug or Sept, cant remember which month off the top of my head.
I would imagine you could order a 200 right up until the day before the MK4 is officially available in the showrooms.
The RS version won't be out for at least another 8 months or so and that would give Renaultsport plenty of time to finish production of the 200 and sort the production line out for the new version.
I ordered mine 15th January and it not gonna be here while end of march but that's the options that make it that way, plenty of basic cups around and a couple of ff with no cup chassis thou