FlyBoyBen
It would really depend on whether the airline could get the corresponding slot into the destination. Places like AMS and LHR are notoriously crowded, especially early morning inbounds. I would say the chances on these routes would be slim. However, routes into less congested airfields may see a benefit, particularly if it is linking into a connecting flight. It also has operational benefits to get the aircraft moving sooner, i.e. an extra half an hour to play catch up for any delays, bringing subsequent flights forward in competition with other carriers.