Yep. Man City should have titles stripped, too.
If found guilty, I doubt they'd strip titles as who do you award them to? Easy to say 2nd place but the 3rd place team might have ended up with more points if you expunged Man Citys results from those seasons.
I reckon they'll be demoted to L1 or L2 if found guilty of all charges. They'll keep titles but end up a couple of divisions lower.
Swindon were demoted from the old Division 1 (EPL) after winning promotion to there, back down to Division 3 based on breaching rules 35 times regarding illegal payments to players (albeit, they did appeal and go back to Div 2 (Championship). Man City have 3 times the amount of charges levied against them. Albeit different types of charges, they're just as serious.
I can't see anything other than demotion if they're found guilty. Same with Saracens - they kept their titles but were relegated.