What is the possibility of a class action lawsuit being brought by any club that feels their cheating has impacted their earnings since 2008?
Surely if they are found guilty then there is a real case for one.
Their guilt is an inevitability at this stage. City have invested huge resources into delay tactics rather than fighting the claims. The timeline was posted earlier in this thread but essentially the hearing could have been completed over 3 years ago.
Kicking the can down the road isn't the action of an entity believing they can defend their actions. Let's not forget this is a civil matter too. The EPL need to prove City probably broke their rules. They have to prove it is more likely, than not, the allegations occured.
Once proven, I suspect City are in for a decade of legal issues. There are the criminal issues. False accounting (Section 17 Theft Act 1968) seems nailed on for the high level executives. Concealing criminal property (Section 327 POCA 2000) which is effectively money laundering. Then you have the fact this is effectively a complex fraud (resists making a Fraudiola reference). City have repeatedly made false representations from which they gained, and others were exposed to a risk of loss (Section 2 Fraud Act 2006). The most appropriate primacy for the investigation is likely the National Crime Agency (NCA) and Serious Fraud Office (SFO). That'll take a few years to unpick I suspect, a few convictions coming out of that. Custody threshold definitely passed when considering the societal importance of sport and the reputational damage to one of our biggest global exports.
Then all the civil stuff will begin. Every time City have finished ahead of another team, they've cost each team ~£1m in finishing position prize money. Years they've won, that's £19m. Second, £18m, etc. 15 years of it going to be around £200m. Then you have teams being relegated because City were cheating to stay in the league. Then the teams losing out on Champions League, Europa League and Conference League football because of a cheating team finishing ahead. The sponsorship implications of those losses. City have probably cost other teams around £750-1bn in lost revenues, just on those factors alone.
In short, I'd expect a couple of decent prison sentences for the coordinators of the conspiracy to defraud and financial ruin for City but likely playing out until 2035.