I agree with the possibility of all of that. But I think some of the underperforming early vote may be due to polling station operating location and hours changes (for some counties) if there were any (reported in some main stream news headlines, and which I still would like to look at to understand). And so some of that “would-be early vote” could appear later on election day. That said, I don’t know the full details of those news articles yet.
I agree it will get closer to 2012 #s as time moves on. After day 1 of in person voting, Democrats were -11% and Republicans were -7%. After day 3 of in person voting it was -10% and -6%, so both improved a bit in day #2 and #3 relative to the first day compared to 2012. The big question is will blacks show up or not. So far, they haven’t while whites have showed up in the same #s (down on Ds and Rs, up big in Indies).