Agree with you on most parts. The 18 year old doesn't really care about politics. At that stage, it's just your love for your country, or love for the profession, or love for some technical aspect. For me, it was because I loved helicopters and aviation. Mulk, qurbani, fauj etc. came later
For others it might be tanks, for some it might be something else.
Also it needs to be taken into account that for better or for worse, the army, just like CSS, presents itself as perhaps the only means in Pakistan through which you can climb the social ladder. So for a kid from let's say Chiniot or Dera Bugti or Kalat, the army is perhaps his best opportunity in making a good life for himself and his family. So why would they shy away from recruitment?
Also, I was told this a while ago, that the recruitment demographics of the army have greatly changed as compared to say 2/3 decades ago. The kind of kid that is now giving ISSB is now much more diverse than before and comes from all sorts of backgrounds.
So to answer the OP question, the recruitment numbers probably haven't taken a hit. But the type of recruitment has certainly changed, but not due to the recent fiascos.