I haven't yet seen such a posting for any European carrier, including BA, but that apparently doesn't dispel the conclusion, based totally on this thread it seems, that European carriers oversell the premium cabins all the time. That's not my experience.

I'm no "insider", just a frequent traveler. But here's my "evidence", though anecdotal: My colleague and I checked in for a UA flight to NRT last month, whereupon we were told that the J cabin was oversold by 8, with everyone except one checked in. No change of equipment, no weather, no cancellations, no nothing. Just plain old oversold, which they admitted. They didn't mess with us, probably because we're both 1K, but they did ask for volunteers to make other arrangements. The flight left on time.