I don't think they will be reincarnated as the new Manchester City in the Premier League any time soon even though the owner is a very rich man. I'm sure Newcastle United's fan base will grow even more once this team is taken over by its new owners.
Yeah it wont be anytime soon as i think there will be huge improvement next year for sure but not to a point where they will be a some sort of giga club that will sign anyone for the team. That will cost them alot of money and instead of getting the return they were hoping for, I'd say most fans will even criticize the management for trying to do it. Everything needs to start low and steady to build up enough supporter base to support the club for the long run