We can assume that the Chazon Ish would have asked for an exemption no matter the numbers. The question is whether the medine would have agreed and whether agreeing would have even been beneficial to the Torah world.
The other question was whether the Chazon Ish would have wanted the present situation of koilel for all just to avoid the army. This we do not know. If not, then the Chazon Ish might have changed his request or agreed to a limit on the number of exemptions or their duration.
The whole system in EY is so corrupt that the only real Torah choice is “beshitas hakoifrim ein anu makirim.” However, if there were no charedi representatives in Knesset, the medine would have no Jewish identity and charedim would have no services. A separate charedi and dati-leumi state may just happen at the rate things are going, especially in 2 generations when the problem of non-Jewish and non-Arab “Israelis” becomes a major one.