LOL.. it is too early to talk about Kohli's retirement. He has another 4-5 years left with the national team and a few more years with RCB. The situation is different from what we had a few years back, when Mahendra Singh Dhoni was the captain of the national side and the BCCI was looking forward to replace him with Kohli. As of now, there are no good replacements for Kohli. Rohit and Rahul were given their chances, and both of them failed. The BCCI maybe looking forward to having either Shreyas or Rishabh as the captain in the long term, but these two doesn't have the experience as of now.
That may be one reason Kohli is not worried about his current form. Rohit has just taken over capacity and he need atleast a year to prove that he is fit or unfit for the job. This also proves that no matter how good a player is you need to have one or two replacement ready to avoid such situations.