Have the same issue for my BOS-LHR on 7 Sep. My booking still shows me as on it but I cannot actually book the flight online. I tweeted at Virgin who said that they confirmed that flight is still operating. Not sure if I should believe that?? Had a similar issue in the past with DL on BOS-CUN which wasn't showing up to book online but my booking still showed me on it. It wasn't until 3-4 days later that I was officially changed off of it and rebooked on a connecting option. Could I expect something similar from VS?