If they relegate City, they're destroying their own league. So with that in mind, they wont relegate City.
What they should do is instead of a 450 point deduction or whatever, is spread it out over the amount of years that they have transgressed, assuming they are found guilty. I'd give them 45 points deduction at the start of the season for 10 years, or however it would work out. Make them pay for dragging it our or so long. As clearly, there's no point fining them as the country is so rich. I have my suspicions though that this will be decided in a foreign embassy long before any commission get to set a ruling.
Lets not forget though that we already know they are guilty in some portion as they were found guilty by UEFA, they just couldn't do anything as theirs was time bound, so they got a way with a fine.