Let's take a look into that demo and then decide based on its content. 
Doesn't matter about the demo.. 7 day to request unban rule.
Well, alot of people had their chances so why not have a look at that demo...
Exactly. Each case should be treated separately. 
Then the rule should be removed. Either enforce the rule or get rid of it.
You just saying it so easy!
What about the guys who got banned
before the rule was made? They didnt knew about it and came back to make an unban request, but getting denied as for the rest. Some pro's getting banned are not even bothered to make an unban request, they just move on. But there are times like a fter few months they come around again and see being banned...
My point is, yeah, there SHOULD be exceptions for people who didnt knew. Also if the rule is so important, why not add it on every server at "AmbrosiaInfo" saying "If you get banned, make an unban reqest within 7 days... etc etc."