We live within 1 mile of LCY so get to see the weather every day. This year, although I may have missed some, the only bad morning seems to have been last Sunday morning, when LCY was of course closed.
The misinformation is not just confined to BA, but afflicts the LCY arrivals/departures website, their feed to BBC Teletext page 458, and indeed their FIDS screens inside the terminal. LCY are determined to use the arrival and departure information as a plug for their services, and not to give useful operating information. Thus flight detail for 12 hours or more ahead is shown, but little/no useful information on actual operations.
Flights are cleared from the FIDS immediately after arrival, in some cases where pax still have not come out into the terminal, leaving those waiting for them quite misinformed. This leads to the ridiculous situation in the evening where more than half the flights shown are for the following day.
Details of cancelled departures are posted only at the last minute, yet the inbound may have been cancelled several hours before.
At times of complete closure due to fog you can find that half the flights are shown as cancelled and half not, this corresponds fairly closely to which handling agent is used.
No information is ever shown about diverted inbounds. They seem unable to state "Diverted to Southend", I can only attribute this to the policy having been determined by Marketing, who find displaying information about diversions embarrassing.
It is in the airport's interests, of course, to have delayed pax hanging about for hours, eating up the overpriced food, or parking in the car park for flights cancelled long ago.
I am aware that cancellation/delay decisions are constantly being updated. I am also aware that where such is decided it is regularly not passed on to passengers. And that showing no information about a departure when the inbound has been cancelled is plainly ridiculous.