With all due respect to the Rav and his Torah, he still represents the State of Israel. This is plain and obvious.
Therefore, I can see why going to the siyum would have been problematic for those who so strongly *and correctly* understand that Zionism is not Judaism, as their attendance would have implied an acceptance of halachic legitimacy of the State of Israel, which of course is not the case.
Again, the only “sad” part about this is the tremendous damage the Zionists have inflicted on our people. Otherwise, this has nothing to do with Mashiach, and I disagree with Mod/42 that they should have gone “even though” the Rav was there. Besides, if it bothers “the Satmar”, unless they came to protest in your face, then why not live and let live? There is anyways no chiyuv to go to a Siyum HaShas.
Unlike the Internet Asifa, incidentally, nobody was told they should attend this siyum. So it would appear more appropriate to have attended the Asifa, where there was a wide-spread call for attendance, than the Siyum, if one were going to choose only one event.
It seems the Siyum was a 100% Kiddush Hashem. B”H!
May the next one be in the rebuilt B”H with the true geulah BB”A.