That wouldn’t prevent you from having a blood transfusion, they would just refuse to pay for it under their health insurance plan.
Correct.
Would they, though? I don't think they believe that having a blood transfusion is in the same category as having an abortion is for the Hobby Lobby people or that the same issues are concerned. They don't regard it, for example, as the taking of a human life, but just as something they are forbidden from doing, as people in some religions don't drink or eat pork or beef. I'd have to find out more about the matter, though.