I am new to VX so please bear with me.

I have just booked a reservation in Main Cabin Select (Z fare class) for a flight far in the future (April 2017). 3 passengers, including a child, so we'd like to sit next to each other in row 3.

When I go to the map to assign seats, every single seat is grayed out, including row 3. Is this because the flight is too far out in the future? What will happen on the day of flight if seats in row 3 are taken? The child cannot be in an exit row, so will they split us up and re-seat... where?