Interesting. By the logic proposed here, known old alt accounts should get a red tag too since "the early days are different" reason is not acceptable.
There is no rule ever regarding Alt accounts. If you mean Alt accounts should have the same Bans imposed then I agree, anything less is Ban evasion. There is nothing stating that in the early days Plagiarism was acceptable, it was less of an issue and not monetized afaik.
Then, now they (unbanned users) started to ask for reduce sentences of their signature bans. It is a basic greedy instinct of human. We might see a new wave of suggestion topics on reduction of signature ban period. 
We've already seen one, though it wasn't started by a banned user. I believe maybe because some of their chums received the reduced sentence and they still found it harsh.
I think at the very least state the reason why the account has been banned? I always see posts asking why their old account has been banned from the forum (hence I assume that no one will state the reason of banning your account the moment you are banned?)
They do receive the basic message stating "plagiarism or spam". I've seen it mentioned by a Global Mod that it is to labor intensive to give everyone a reference to why they are banned. So for the ones who do create an appeal I've seen staff chime in with why they were banned. Don't forget a lot of those posts wondering why are people who know exactly what they did who try to play some sympathy card or give an improbable explanation.