I don’t think it is realistic, but if they had to go to the Championship, do you think there will be players who want to stay and get up again, or they just look for an other Club? Which club would even be a possibility for the biggest city stars?
Sorry for my english
There is no mechanism to ban, or relegate from the PL. Only a points deduction, which may lead to a relegation. If that happened city would return in a year and then struggle with £ for a few years and be mid table.