NM's post belies a bigger problem in the way BA handles re-seating of pax when there's been a change of config or aircraft.
I've recently been re-seated twice - in spite of having pre-allocated seats - when travelling on intra-European flights. Thankfully I wasn't involuntarily downgraded but I was slightly miffed by the way BA handled the situation (or didn't...)
The first I knew about the re-seating was when I double checked the earlier record I'd kept of my pre-allocated seats. Fair enough that pax get moved around when a config or aircraft changes, but BA should be telling people this when they check in.
The ops manager at one of the airports I flew from told me that the check-in staff will be none the wiser [true?] and that seating is handled by BA centrally, not locally.
If this is the case, why doesn't BA think about getting a message through to its local operations so that ground staff there can warn pax about to fly? Seems like a small gesture would go a long way...