Okay, I was going to take a nap, so, while I was trying to sleep the topic of "How could people forget about Ivor being a member of the orden of the stone so easily?" came to my mind. (This is going to be a long one, sorry for the long text)
Someone a weeks ago talked about this strange thing, because the og orden look like they're in their 50s maybe almost 60s. There are not enought time to people forget about Ivor to the point that they just don't recognize him at all (literally in S1EP1 when Ivor ruin the event, Jesse's gang are just "who tf is this guy?" and "why Gabriel knows him?"). The og order were celebrities when they were still a team, so people knew Ivor and he was also treated as a heroe, so, how did the people forget?
The original anon came up with two possibilities:
1. MCSM characters just don't grow up, they just spawn and they look like that forever.
I don't believe this (I think the anon didn't agree also). We have a portrait of Harper looking younger with black hair instead of her grey hair that she has now. So people can grow up. So the next thing was
2. MCSM characters grow up but they do it slower than humans in real life.
This sounds more posible because in this case we may have the enought time to people forget about him. But it doesn't still fit to me. You just don't forget something like that, it's like if in irl society just forget about Paul McCartney being a Beatle because it had passed 40 years or more. It still odd for a celebrity just being forgotten like that, even more if Ivor still alive.
So, here is my take about the topic:
The main characters, when they find out the truth in the book of the temple in EP1, describe it as "he was erased from history", so, how if we take this more literal?
It seems like no records remain to show that Ivor was a member of the order, except the book in the temple. There are for sure books about the other members, we know that because the narrator read us the same version of the book but without Ivor at the beginning. Then, there is, as I said before, the fact that the people don't recognize Ivor at all, like some type of collective amnesia. But how are these two things possible?
The command block. Hear me out on this. When Ivor has this argument with the order and they all agree to keep the secret, even Ivor promise it, what if they also decided to literally erased Ivor from their history with the command block. Why? The other members during EP1 to EP4 don't see Ivor as someone you can trust. Even if he promised to keep the secret, what if he just change his mind one day? Ivor as a member of the order has the authority to people believe in him, but Ivor as a nobody the situation change. No one would believe a random saying that their heroes are a fraud.
You might be wondering why then Ivor didn't change this at some point with the command block instead of the whole wither thing, and this is my answer:
Ivor promised, he really has no intention of breaking his promise (he said it himself in EP4), so probably he also agree with this because he won't tell people anyway, not with his words.
Ivor in the game is resentful because of the order lying to people about they being the greatest heroes of all times, he's not that much resentful about the order earesing him. In EP4 finale if you choose to tell the truth, you just mention that they were cheaters, but you don't tell about Ivor being a member, and he's is happy with that. He doesn't need to being remember as an order member because of the command block he never was a real heroe, so what's the point? He's just happy with the fact that people know the truth.
(If you've made it this far, thanks for reading! Sorry for the long text but I'm bad at summarizing my theories. I may have missed some information in my final conclusion, so if there are any mistakes let me know.)