There was once a very well known and respected Rav who was in my shul for Shabbos during the summer. I saw his wife in the shul wearing short sleeves.
I won’t write the name of the Rav because as I said, he’s extremely well known and highly respected. I’d like for it to stay that way. If I wrote his name here, he would likely be made fun of, and some people would not respect him as much.
Suffice it to say that there is at least one major Rav that I know of who holds elbows don’t need to be completely covered.