Yes this is true - might i also add that a user doesn't neccassarily know that a team has been banned for cheating, all we see is the team turn bot.
So as far as we know, he just hasnt logged on. Some user's may suspect another user is cheating, report him, and then notice that he turns bot some time later, and deduce that he has been banned.
But because they do not release information about if a team has been banned or not, how would you ever know for sure?
I do agree with the idea in principle. In real life, league teams that are caught cheating get zero league points, and finish last, or equivilent.... but because the end result of a banned team is the same result as a team going bot, you would need to apply this rule to teams turning bot, which, i dont think is fair/feasable.