I hate to bring this up again, but the PM that the banned user gets really ought to contain at least one example of the plagiarism offense so they don't waste people's time playing ignorant and/or demanding proof
But we're both well aware that it won't stop ban appeal threads right,whether there's an indicator to the plagiarised posts,a message stating why they've been banned or even flat out proof of numerous offences.
Just for the sake of it,they would still make threads about it,either it was a mistake and they should be forgiven etc, either way,nothing has been solved as we'll still be getting the ban appeals.
The only advantage would be that we wouldn't have to go through the strenous task of rummaging through their post history to see why they've actually been banned,it's actually not an easy task to do,and since the mods are the first ones privy to the reported plagiarised content,it should be easier for them to include it,valid suggestion.
So it could help a bit.