I had read that departure times for egypt air flights were goals, not something set in stone (so to speak). Such appears to be the case today as our flight from London to Cairo is likely to leave around 6pm, 4 hours late.
London Heathrow is an interesting airport; they don’t let you know the gate number for your flight until 30 minutes before you leave. Why? So they can keep you in the huge shopping area in the middle of the terminal. Smart people.
Years ago, I asked a British Airways agent at Heathrow why they didn’t disclose the gate number until just before the flight. She told me it was an anti-terrorism measure. This was before 9/11.