if I were in a position that I needed blood I would just hope they had my blood type

Would not even occur to me to be curious. There is no difference in blood between races although there are some blood related disorders, such as sickle cell anemia that are more prevalent in one race than another. However, that sort of thing is screened for when blood is collected.
If it were an organ donation instead of blood, I would be curious about who it was from, not for race/ethnicity reasons but because another family (most likely) suffered a loss for me to live and I would be curious about that person, although it is often against policy to reveal who donors were.