ZB:
Please forgive me. No, it does not.
Just because the Zionists invented a flag for their idolatrous State, that does not therefore automatically make that flag, halachicly, an object of A”Z, as Rav Moshe indicated.
You are the one who is positing that
A) their flag is “the key symbol and object of zionism” and that
B) therefore this would automatically make that an object of A”Z.
(As it happens, I would humbly submit that the Menorah which the Zionists have ripped off from us for their emblem would far better fit your criteria.)
Regardless, Rav Moshe stated that, from the viewpoint of halacha, neither A nor B is true.
As well, Rav Moshe’s calling them “reshaim” does not mean that Rav Moshe meant to exclude them from being ovdei A”Z, avi avos haTuma or anything else.
The greatest Torah sages from the past century have called Zionism both idolatry and heresy. To argue that Rav Moshe felt otherwise, based on conjecture from and diyukim in this teshuva, is impossible.