the study is BS.
I agree, most studies like that are produced and paid for by groups with the express agenda of trying to control someone elses behavior. I treat everything the same, if on MY property, and causing damage, it is eliminated, from bugs to bears, I have always handled pest this way, and will continue to do so. Your investment in your bee's far outweighs a couple of birds. Especially swallows, which are everywhere.
Before any self righteous bird lover chimes in, I have bird boxes up all over the yard, we have bluebirds and Wrens and they do a great job of keeping bugs out of the garden. If they become a problem for my bee's, they will be evicted.