AA is blocking some seats and there appears to be no pattern on whether those F seats get assigned. Some flights the first row is blocked, others they are given to those on the upgrade list. As a PP every single one of my upgrades has cleared, almost all at T-72. Given the number of business travelers not flying and that probably won't fly until the entire social distancing/mask wearing thing is over as an EXP you should be clearing just about every flight and at the T-100 window.