Agreed, it's not official until it's official. There can be a ton of fuckery between now and the convention. My gut tells me they are going to do the virtual roll call just to be on the safe side. (But, wtf do I know???)
I saw a tweet today that truly amused me (it was from a prominent account but I can't recall who it was)
They suggested that Harris nominate Biden as her VP. I don't think that's actually legal - you can only serve two terms as POTUS so I'd assume the same goes for VP. He's got two terms as VP and one as POTUS. Twitter is a hellhole, but it amuses the fuck out of me, and I can't quit it.