Adele's going diamond last era should have been a clue that she would break records the next era, but [some] people totally thought 25 would flop out of the gate, at least in relation to 21's monstrous success.
Let me go look at some older threads here from like 2013 when someone asked could she break first week records with her third album...
That was a low prediction, she did that with 21 a year after it's release.
It didn't seem low at the time. I said to myself that anything 700K would be brilliant! I just was sure that she'd left it a bit too long and people wouldn't be here for her as much! I was so wrong!