It's just occured to me (while looking at how much the CE cabin is filling up for a forthcoming flight.

The CE cabin has 3 rows of 2 + 2 on the seatmap.
Row 1 is blocked (to silvers and payers)
rows 2 and 3 are all but full now.

Question: If I don't grab a seat now, will I automatically be put into row1 (come T-24)?

What if the eighth seat gets taken in row 2/3 before T-24 and I try to book my seat?

I intend to wait until T-24 and nab row 1, but the question tweaks my curiosity.