Wonder what happened to Dhawan suddenly. Playing such a fine flawless innings. Not the first time in ODI's though. Seems to be badly out of touch in Tests, comes back strongly in ODI's. Plays a scratchy innings in T20's. So he is ideally suited for ODI's where he has the game to tackle any situations easily. In tests an opening or top order batsmen needs to block and leave most balls playing patiently like a Vijay and Pujara. In T20's one has to go bang bang right from the start like a Rahul or Shreyas Iyer. But in ODI's he has nothing to worry about. Just play his natural game. So now we have so many individual format specialists. Its just that the team management has to understand that and select players accordingly.
Now a days, even MS Dhoni is ideally suited for ODI's as always like Dhawan. Its upto him to decide on his T20I carrier. But being a wicket keeper batsmen, he might just groom an younger like Pant or Ishaan for T20I's and gradually take his future from there based on how they respond in terms of performance. In Dhoni we had a very fit injury free wicket keeper batsmen for almost 14 years so we never had to look for a secondary option throughout his carrier.