Owing 'millions' could easily be 3-4 million which is chicken feed to a PL club. I wouldn't take Daily Fascist clickbait as a basis for forming an opinion on the financial rules and how they're enforced.
For instance, Forest only signed so many players because they got promoted with a squad that was largely made up of players who were either on loan or coming to the end of their contracts. High squad turnovers each season aren't that unusual outside the PL and Forest's long term planning at the time was probably not taking promotion and survival in the PL as a given.
They spent the best part of £200M last season but most of that was on players 25 or under. There was loans and a couple of 1 year deals to bridge a gap and they stayed up. They seem to have reigned it right in this year but are still looking to buy - not exactly the actions of a club with administration hanging over them.
Even if they go down they'll likely be in a better financial position than they were before promotion. Fairly young squad, no ridiculous contracts for past it players, 2 seasons PL TV money and parachute payments on top. And given they only came up last year I'd imagine a lot of the deals they've given out since then have had clauses in as they knew full well a relegation battle was in the offing given their unlikely promotion.
From the outside looking in they don't strike me as a basketcase club.