...but you can't stand in the way of progress...
I assume you mean that if the 'progress' is an improvement then it should proceed unhindered. This is not a comment just about this situation or aviation in general; it could be applied to transport industries, health industries, engineering industries etc. It then becomes a question of who decides if it is an improvement for all concerned and not just the money men.
Robots in car manufacturing put a lot of people out of work. Has it produced better cars at a cheaper price? Has the working environment of the car builders improved? Has it increased the financial strength of the companies? I suspect it is yes to all 3. Thus there has been an overall benefit to all involved in the chain of car manufacturing & sales. Sadly there were many sacrificial lambs.
In the aviation scenario it seems likely it is driven only by money/profit etc. Will it have any detrimental effect on safety, passenger experience? It should not in the former and they will vote with their feet if it does in the latter. From the avoidance of sacrificial lambs point of view freedom of movement of labour within EU is an accepted fact. The governments of EU countries have a duty of care to not allow their citizens to be effected detrimentally by losing jobs to outsiders. The USA & green card system has been doing that for decades, as have other countries. That is to an accepted fact. Will this move by NAS fly in the face of that philosophy? I do not have enough information to make a categoric decision. We should be able to trust the powers that be to have a strong oversight and to carry out their duty of care, but if the governments leave it purely up to the XAA's to issue an AOC yes or no, then the outcome might be not what is best. The XAA's are not there to protect local jobs but oversee and decide on the suitability and legality of XYZ to operate within their territory and dot the i's & cross all the t's. Work permits are not their remit.
Perhaps the various unions are trying to wake up the conscience of the governments. Are they fighting a lost cause and will 'progress' march on? We wait and see, but it should not be a call made on allowing a company to increase its profits at the expense of the local citizens of all the EU countries involved. Flags of convenience should not feature in EU operations.