No saying anyone needs to be removed now, but this year they have close to 20 ODIs, a good opportunity to give some games to Tilak, Samson, Kishan as well as Jaiswal. They need to try out the potential replacements.
I am pretty sure Gambhir doesn't want Rohit as he will be beyond 40 next year, plus he's a poor fielder thesedays, so as soon as Rohit has a couple of bad series, Gambhir will probably want him out. Rohit will really have to stay in form. He hasn't done much since the Australia series anyway. Gambhir doesn't seem to like Iyer either as we have seen in T20I selections. Iyer didn't have a good series vs NZ too.
Let's not forget Gambhir will now command so much more power than ever before, after winning the T20 WC. He will undoubtedly try to bring in his T20 stars. Samson, Kishan, Tilak etc. If Rahul keeps his form, there's a possibility he is removed from keeping and asked to open in SA conditions (along with Gill) as he is already a Test opener. In this case he can bring in Ishan or Samson as the keeper. Gambhir is certainly not going to ...just ignore his T20 world cup winners.
He already fired shots in the PC after the final. Calling out milestone chasers. So it's pretty evident big changes are going to happen. He also mentioned that he was not happy with the results in the ODIs, specifically stating that India had lost two of their last three ODI series.