Yes, but there can be long delays between a donation happening and updates. Coordinating donations can be non-trivial, especially when flash crowds appear (e.g. sob story on reddit).
Also, such a randomized approach is not necessary if one can just donate small amounts to multiple projects instead (i.e. if transaction fees are not a problem).
I once donated some money to VillageReach a few minutes before getting the GiveWell newsletter issue announcing that VillageReach wasn’t going to be among the top charities in the next update because their founding gap had mostly closed and encouraging people to wait for the next update before deciding whom to donate money to. True story!