I've never had an op-up to F, never flown F. Sometimes J has been full and I've still not been chosen for an upgrade but have seen others receiving new boarding passes (not necessarily from J to F though).

I've had a few OPs to CE from Y on Euro flights, but probably only 3 sectors in the past year and I'm on BA planes nearly every week.

Seems OP-UPs are less common these days. Also if passenger numbers dwindle then maybe even less?