It seems like the motto of the Dravid era is to maintain the same playing XI with a broadly similar tactic between XIs and to keep refreshing the 15 man squad to trial out options. Honestly? I don't mind this approach. It does give a sense of security to the 'one last ride' blokes like DK and the 'up and coming' blokes like Avesh. The main worry seems to be our complete lack of strong leadership candidates which seems to have carried over from the previous era where it was basically Kohli, Rohit, Rahane and MSD with a pinch of Dhawan and Bhuvi.
I'm curious about how well Harshal Patel will play in Australia. On one hand, he bowls the sort of pace that can get thrashed if batters line him up. On the other hand, bowlers like Richardson (the slower one) and Tye have found a modicum of success in Australia with their variations. They use the bigger side boundaries to their advantage particularly with their slower and wider deliveries. Harshal can also bat adequately although he's yet to show that at higher levels like Thakur has done. His presence alongside Bhuvi's also means that Bumrah will be the only quicker pacer we have in the playing XI. Ideally, you'd want another quicker bowler like Shami on the Aussie pitches. We might also go with two spinners like originally planned in 2020 with the bigger Aussie grounds being the reason.
I don't think the batting will be subject to much change, barring some shocking exclusions or pull-outs. Rahul, Rohit, Kohli are guaranteed spots while Hardik, SKY and Jadeja are almost guaranteed spots too. From the way Dravid speaks of Pant, I would put him in there but his form is just too shocking to merit a place. DK vs Pant will probably be the last battle whilst we have Kishan, Shreyas and Venky battling for the reserve spots and challenging the first-team players. Unless the rumours of an expanded squad size are true in which case I expect them all to be picked.