That's what I thought at first, but I checked and VS27 on Oct 31st is still scheduled at 11:15 and it's a 747
For that in-between period (end BST - end EDT) A330s are scheduled at 10:40 and 747s at 11:15
It's true that the Airbus is a tad slower than the 747 at cruise speed.
It's marginal (a few mph) on a short distance, but for a TATL it can mean 20 or more minutes.
Well, at least you get to ride a much newer plane (and IMHO a better plane to fly on, except for that bubble we all got to love at some point)