Why not? Rudiger won the Champions League then fucked off from Chelsea when they didn't give him the 400k a week he wanted. Two of these players are at the age where this is their last chance to get a big contract at a club that's still competing. It's probably both of their last chance to play in La Liga if that's something they're interested in. Salah has been the best player in the league this year, and he'd be well within his rights to demand to be one of the highest paid players in the league. And then with Alexander-Arnold, if those two leave, he has to decide whether he trusts the board to bring in world class replacements. If not, he might think it's time to leave a sinking ship even if they look like winning the league this year.