The threats are all part of the play, in reality they're not going to do shit. It's just two sides taking their most extreme position in the negotiations, eventually they'll meet each other in the middle.
The FIFA won't ban the best players in the world, they're a corrupt organisation who've been getting filthy rich based off the star power of these very players.
Similar goes for UEFA, why on earth would they punish the clubs that have been bringing all the money in and literally have billions of fans worldwide? Imagine them banning those 12 clubs from the CL, good luck selling a Leicester City vs Villareal CL semi-final next year, I bet billions of fans and sponsors worldwide are really looking forward to that, and willing to splash out big. Real star appeal for the biggest brands.
Same goes for the FA, why on earth would they shoot themselves in the foot by punishing the most popular clubs that have been bringing in the most money?
I don't understand why people would like to see punishment either. You want United to get punishment for trying to take more money for themselves, which is good for the club, instead of letting it flow to the UEFA? Why?