Even with all your justifications, which I'll stipulate are true (a CCS will reduce resonances, divert more output to the load, and lower distortion), there are good reasons to use a choke load. Chokes store energy and can swing above the power supply. As a consequence, a CCS loaded tube needs a power supply more than double the voltage of one with a choke load. Besides the huge reduction in efficiency and the need to dissipate the heat, this also requires the use of a very different class of high voltage components and very different construction techniques. Building a 400V supply is trivial. Building an 800V one is not.
Additionally, while the choke load will have more distortion, almost all of it is at low frequencies where distortion is considerably less audible. Your 200H choke may only provide a 50K load at 40Hz, but at 1000Hz it is well above 1M2 Ohm which is on par with a CCS.
For reasons of safety, personal comfort in working with high voltages, or possibly even cost, the trade off of slightly increased low frequency distortion chokes may be justified in some cases. You don't have to use them, but it does not mean that they are a blanket bad idea.
And Lundahl makes a 270H choke, so 70K at 40Hz.