As for a voter saying, "I would have voted differently had the change been in effect when I early voted," it would be the same as if a voter said, "If I had known about this latest scandal, I would have voted differently." Once the vote has been submitted -- early or otherwise -- the vote stands. There is no legal recourse for a pre-scandal ballot or a post-scandal ballot. According to law, your vote is for electors pledged to a party's ticket.
I could see major political issues, but not legal issues. The most I could see is a state legislature intervening to "correct" the names for the slate of party electors.
No, it’s not nearly the same. If a totally different person is on there, you’re just not going to win the “legal” argument that “No, you’ve voting for an elector.” That’s a Ted Cruz-type move, but it wouldn’t hold up in the court of public justice-—even among a lot of Dems. So if state legislatures (not OH, cause that’s R, not AZ cause that’s R, don’t know right now what FL and NC and VA are, but right there are the only ones you’d have to worry about) do “correct the names” of the electors, the suits would claim that in fact people voted for different electors already.
You cannot legally get around the fact that VOTING HAS ALREADY STARTED and Bush v. Gore will be the yardstick against which this stuff is measured.