I suspect the issue whilst a potential concern, is probably just that.
Politically it would be impossible for EASA to let these aircraft become grounded because of approval issues. Like much 'continental' legislation I suspect the arrangements have largely all been made but EASA's processes are simply too slow to keep up.
These aircraft are the fore runners of what will effectively be the European LSA category - if EASA allow that to die, the political fall out would remove many EASA people from their comfortable existance. Remember this category has come about because these companies are selling the vast majority of their output to the US but cannot sell it into the EU.
The CAA have a point, but I suspect much of it is NIMBY-ism and being able to heighlight the potenital downsides.