The area round there was already earmarked for government, local council and EU money when they were proposing the 'super casino' idea. Now that's not happening, then it's Manchester City's new owners who'll be getting the benefits.
This isn't the new owners pumping in a billion pounds to continue to regenerate a formerly run-down part of Manchester - this is the taxpayer continuing to fund something that would have happened with or without Manchester City's new owners. The new owners are just getting some nice perks for putting in a bit of their own cash - new training facilities plus possible stadium expansion without having to worry that the city council will veto the planning applications. You're just starting to see why they thought Manchester City was a good investment for them (edit: especially if they manage to get ownership of their stadium as a result of this....).
So it's a bit 'meh' for me - wouldn't be too surprised if there was an inquiry into whether this is the right use of public money (much as Everton's Tesco stadium proposal was subject to), although I'd guess that the government will want to let it sail through after the messing about over the super casino plans.