At the risk of teaching you to suck eggs as I am sure you already did your research before qualifying Gold…

Whilst American carriers upgrade their regular flyers as a matter of course, it is more the case that BA especially only upgrades when they have operational needs to do so. So people with status will frequently book into the world traveller plus section on a busy flight as they increase the chances of being upgraded to club.

Sometimes your status can work against you as the BA algorithms will decide to upgrade somebody without status to “give them a taste” of what they’re missing by not flying the upgraded class.

generally checking something like expert Flyer and looking at the loads in the cabin you have booked, the cabin above, and the cabin below will give you some indications of the likelihood of operational upgrades.