Can grated coconut be frozen to be used later for coconut milk, flour and dried coconut?

You can definitely freeze grated coconut; they will last about 1/2 a year in the freezer. For easy portioning, pack them into ice cube trays, freeze, and then transfer them into a bag. Or roll little balls of the coconut, arrange on a sheet tray, then transfer to a bag. Either way.
As far as them being dried and used for flour or used for milk, I'm not positive on that. But I'm going to guess yes.