If I grew blue lake pole and bush beans and they crossed, how would I know?
If you saved the seeds and planted them next year, you might get something different than either one. Probably would be shorter climbing beans but you never know till you try.
Beans often self-pollinate before the blossoms even open up. That's one reason why they are such good seed saver crops. I'm not sure what commercial growers do to ensure cross-pollination. But again, the only way to know would be to plant some saved seeds.