The organization said that these measures will ultimately lead to restrictions on the UNRWA definition of refugee, presumably to bring it in line with the UN definition.
It said that if the US must approve UNRWA Palestinian school curricula, it is "stripping the Palestinian curricula of any contents seen as discriminatory or inciting against the Israeli occupation, such as referring to historical Palestine."
Judging from what I've seen in their curricula, that isn't the issue.
Another NGO, the Democratic Gathering of UNRWA workers, the trade union of the Popular Front for the Liberation of Palestine, terror group, condemned UNRWA supposedly punishing workers who post incitement on their social media, saying that this is a violation of freedom of speech.
It is normal for Western corporations to prohibit employees from engaging in controversial topics on social media when they can be identified as being employees of that company. It isn't stopping freedom of speech.