Gaikwad made couple of 50s for them at the top orders so i don't think they are going to bench him. He should get at least 2-3 games but if he fails then may be Sam Curran could replace him or Roy if CSK buy him.
Then again you need 4 overseas players. Chawla and Bajji are not there so i am not sure if they going to opt for 2 overseas opener (Faf-Roy). Faf,Curran and Bravo(if he's fit) seems fix. They should go with the another overseas bowler in the squad, on spin track Tahir/Satner and on fast may be Hazelwood/Ngidi.
Last year, there were some rumors regarding the increase in limit for overseas players from 4 to 5. But I haven't heard anything on that subject recently and it looks like the limit is going to stay at 4. I agree that du Plessis and Curran seems to be permanent fixtures. But I am not that sure about Bravo. His form has declined recently and he has gone through serious injuries. Gaikwad may get a couple of outings, but if he fails to perform, then he'll be dropped. Tahir is around 42 years old, and I am not sure whether he'll be fit enough for IPL 2021. For the pace department, they have promising Indian players such as Shardul, KM Asif and Deepak Chahar. For spin also, they have Jadeja and Karn Sharma. They may need only one overseas player for the bowling department.
The clear picture will be available only after February 11th, after the auctions.