You can't strip titles and that won't happen. Not because it would be undeserved, but because its imposible to convert the currency of corruption into impact on the pitch. You can say, well they injected about 500m during the three year period, which means they wouldn't have bought so and so - but in reality, you can't argue this with any precision as to what would or would not happen. Who would they buy if not, how would these other players play and so on. The impact of financial cheating on the results on the pitch is not nothing, its likely quite enormous - but it can't be measured with any precision, which is why they'll never lose the trophies they won. We could certainly argue the impact of their financial cheating is more than one point they won titles by, but it is all or nothing argument - either you strip all trophies or you strip none.
To top it off, PL would not even consider pursuing taking titles from them. The damage to the brand would be unimaginable and we need to understand that the City case is all about damage limitation and brand preserving for the PL. They are only going after them because government regulator taking over is seen as more of a threat than City doing whatever the fuck they want and dominating. And they'll be punished, if found guilty, exactly to the point needed to satiate the murmurs for government taking over. Nobody is doing this for justice, or true course correcting - it is being done to wash hands a bit and preserve things as they are. The aim is to change as little as possible while appearing to change a lot.