Earlier quoted context omitted.
I wouldn't say I trust them, but I would say it's the most likely explanation. It could be that they've failed to understand how RSS could help their organization achieve its goals. But it's probably just that RSS isn't worth it to them.
Given that RSS done right is a self-maintaining gimme, I would question the professional judgment of anyone who actually takes the time to remove it.
In general, if they were truly seeing no uptake on it, they could just be justified removing it to decrease their security surface (https://www.acunetix.com/vulnerabilities/web/wordpress-plugi...).
I'd have to know which NGO and what their circumstances are to have a more concrete opinion. With no additional information, I can construct a hypothetical scenario where a reasonable site admin would yank RSS.