This has been done in the past as well, at Benjamin Netanyahu when he was Prime Minister, and probably at other Prime Ministers as well.

Truly such ceremonies on such solemn days are not the time or place for involving politics and screaming political messages at this or that politician.

That being said, the families present are grieving and hurting and cannot really be blamed for it, though by no means must their opinions be given any special importance. 

And, that being said, perhaps it is time for a different approach. Maybe these ceremonies should not include the participation of politicians, especially when people have lost the ability to be non-partisan and accepting of the other.

If the State can decide that the biggest and most anticipated part of the celebration of Independence Day, the fireworks display, can be abandoned to the potential of triggering PTSD in too many people, perhaps the politicians should not be present at these events as their presence triggers the trauma and PTSD of some grieving participants.