I just find it strange that neither BA nor Virgin have any reason stated on their sites up to today.... Just "waiting for update" or "canceled" with no further info and a link to click on that leads to a generic FAQ.
And I wouldn't be surprised if tomorrow the flights still get canx last minute. I think the St Lucia authorities are just re-issuing the notam every 12 hrs or so - hoping each time will be the last..... First they said closed until 31 Oct 2000 UTC then 01 Nov 1600 UTC now it is tomorrow 1100UTC.....