Actually Rafa said that his level is amazing and even he is under that level, but all other are talking about cofidence mostly yes. I think without confidence and self-belief it would be not possible for him to play so consistent high level half year already. But i think they are 2 things that helped him - his forehad, beckhand, serve and other things have been inside him all the time, he just wasn´t able to get 100% of his talent and skills at once out of him. 2 things that did it - confidence - DC, AO and now every title is just making that superconfidence bigger and other thing - his new diet - everyone when feel sick, or is limited with health issues or whathever is not able to be 100% on the court or in other sports too. So since he is much healthier than ever before is logical he can play tennis that he wasn´t able to play before.
Yes, it goes together. Yes, his game has improved, but I think all of us saw this game from time to time -- just not consistently. He has improved his game which improved his confidence which improved his game --etc.