There's a lot of discussion on the FNA website (Fédération Nationale Aéronautique) about this AD at the moment.
General conclusion seems to be that if the spar did have poor quality gluing, the work recommended by the AD isn't going to make it much better. And if it didn't have anything wrong before, it will be weakened by the "repair" work.
It's a bit of a "got to be seen to be doing something" sort of AD.