In the event of a parent or young person not having made a request or representation for a particular school/setting within the specified period of notice the local authority must still always name an educational provision when issuing the final EHCP.
9.88 SEND Code of Practice 2015

This means that if you do not inform the Local Authority (LA) of your preferred school the LA will choose a school for your child to attend. The LAs choice of school will most likely be the closest mainstream school to your home address.