Question - does anyone know if the two availability sets are the same?

Skywards (I didn't realise this until recently) is showing Award Ticket availability online in calendarised form. Very handy, it blacks out days where no award ticket is available on your route etc.

But regarding upgrade availability, that's a guessing game, or you just ring Skywards etc.

But is it a reasonable assumption that if there's no award ticket available, then it's a waste of time trying to upgrade to that cabin too?