Drone End of Life Expulsion

Drones being blinded, killed and expelled from the hive. This is not an unfamiliar sight for a beekeeper but it's the first time I've seen this number of expulsions in the matter of a couple of hours.
What makes this interesting is that this is a process usually undertaken by the hive from the middle/end of August. To see this happening at the end of July is remarkable.
I would suggest two explanations:
1) That the hive somehow knows that we won't see much more warm weather this year so is preparing the colony for over-wintering in the usual way - just rather earlier than usual.
2) We did have some quite warm weather early in July and know that Drones have a part to play in ventilating the hive. Perhaps the queen produced additional drones to serve that role and the colony now want rid of them.
Comments please?