Ashley wiped the debt off but still holds Newcastle accountable for it, basically instead of owing whoever they owed money to previously the club owes him directly.
The fastest way for the club to make money is via selling players, second fastest way is by staying in the Premier League and eating off of the cash the league distributes to each club each season. After that, advertisements, match day revenues and other things clubs do to earn money.
Even with that said, the profits that Newcastle have brought in since Ashley took over the club haven't been enough to wipe out the debt. On top of that, according to your club's supporters, he's not applying that money to the debt anyway.
So what does this have to do with finishing top 4?
Nothing, I guess.
Good luck, I hope you enjoy the upcoming season.