If upgrade space is available within an upgrade window, AS should be processing the upgrade waitlist; however, in practice this may not always happen because the system is infamously broken. This failure point leads to pax bypassing the waitlist (eg applying a GGU; purchasing a new ticket that’s a qualifying fare usually results in an immediate upgrade; or, if within T-24 simply checking in may work) or leaving J open for pax to perform legitimate functions such as to change flights, upfare etc.

AS loves to quote the website as policy when it it is in their favor; however, you’ll notice that for this particular topic AS falls short because it is clear what the policy is and that AS doesn’t follow it.