I don't think Felix would be signed permanently considering Atletico Madrid ask too much money for his transfer fee. Maybe he would be loaned again. If he doesn't then I think Morata will be the leaving one. Maybe he would return to Italy if there is still interest from there.
On the other hand, if there is an offer from a Saudi league team, I think that is also quite good considering that so many players of his age choose to end their careers to get a large salary there. Now the decision rests with Alvaro Morata and even if he does eventually leave it will be the umpteenth time at Atletico.
Yes indeed, whatever choice Morata makes I think it will still be a good choice. Because the next decision is Atletico, whether to keep the player or Atletico will decide to sell him. But I think, if Atletico sell him then maybe Atletico can be difficult to compete well in the top four for next season. But yes, because Morata only has one season left on his contract at Atletico. So it is possible that Atletico will sell him in this transfer window of course, so that Atletico will still benefit before Morata finally has a free transfer status at the end of the season.
I think they should not sell it and renew their contracts. Morata is a striker who will give Atletico Madrid huge advantages. If they want to finish at the top of the league, Atletico Madrid must manage to keep him in their squad. If Morata wants to go, of course it's different. If Morata transfers, they can get a good testimonial. This aspect should also be considered.