I personally don't view it as "inappropriate" or unethical, however the reason it may have been rejected is because it could potentially be very shallow. When I say this, I mean that there might not be the depth to your project that markers love and award the higher marks to. Other than that, I...
That's tricky ... while they are both very good topics that should mark pretty good if completed well, the terrorism/anti-islam one is definitely more current and relevant then the refugee one. My friend got an extremely high mark doing anti-islam and terrorism.
However, with that being said...