Strange seat map on 777-200 in Old First
I'm flying on 4/30 from ORD-BRU (UA 972) on a 777-200 in an old style plane. When looking at the seat map in reservations, it shows 1 C, H, 2 C, H, K all available. It doesn't show these as an option in my seat selection, where I'm in row 6 (8 across business). I called up reservations who said these seats are not available. Are they reserving these for higher status customers (I'm silver) or is this a system glitch? Any advice as to how to continue to monitor/give up on getting these former First Class seats?
Thanks in advance