I don't know about other parents, but to me, location is a critical factor. I don't want to move away from HK Island and I don't want my kids to take a long commute. So Island School is not an option for me if I have another choice. It's quite unfortunate that my child will eventually go to their NT location (I think somebody mentioned Tai Wai). He is now at an ESF primary.
I think the school development project was aware of by the thread poster as the school principal explains it clearly during the parent interview. The temp location would most likely land in Shatin.