Stokes was rested from England's tour to Pakistan after a busy summer captaining the Test team and has not played a T20 international since March 2021 but left for Australia on Sunday and is seen as a key part of the full-strength side, despite an underwhelming record across his short-form career.
He has only batted above No. 5 three times in his T20I career, most recently in 2016, but had success opening the batting for Rajasthan Royals in IPL 2020 and will effectively be a straight swap for Ben Duckett at No. 4 in England's World Cup plans.
"One of the things that's been said for a while is that he hasn't had a clear role," Matthew Mott, England's white-ball head coach, said. "And Jos in particular is clear that he's a top-four player. Those conditions in Australia will suit the way he plays. You always have a bit of flexibility with the batting but he will be expected to be higher in the innings.
"I got a couple of texts [from Stokes] on Sunday. He was jumping on that flight ready to go. We've deliberately left him alone. He's had a busy summer. There's a lot of time before that first World Cup game and when we get to Australia, we'll be really clear with everybody on what the expectations are with their roles.
"As good as this tour has been, there's new faces coming in and some leaving as well. So like we try and do for every tour, we'll make sure the starting XI are really clear on what we expect from them and what role we want them to play."
Stokes is likely to be joined in the middle order by Harry Brook, who Mott said "couldn't have done any more" to seal a spot in the World Cup team after a dominant performance at No. 5 during their 4-3 series win in Pakistan.
Brook capped a breakthrough series in international cricket with 46 not out off 29 balls in Sunday's decider in Lahore, making him England's highest run-scorer on the tour with an aggregate of 237 across six innings while striking at 163.01. He was also named Player of the Series.
"He'd have to go pretty close, I think," Mott said. "It depends on what balance we go with - whether we go with an extra batter or an extra allrounder - but he couldn't have done any more to push his case in this series.
"To me, batting at No. 5 is about as hard as it gets. You don't often get it your way: you're either under pressure with early wickets or you're having to throw your wicket away at the end. Whatever the situation was, he always looked like he had a plan. That came out quite clearly and for a young player to be so clear in such a tricky role showed a lot."
Brook spent much of the English summer as the Test team's spare batter, with his playing schedule disrupted as a result. "Brooky has been starved of cricket for a bit," Mott added. "He's watched a lot from the sidelines and he just sees the opportunity. He looked right at home in that pivotal role at No. 5, which is quite difficult normally."
Buttler is due to return in England's three-match series against Australia, which starts in Perth on Sunday, after a lay-off with a calf strain kept him on the sidelines throughout the Pakistan tour, while Liam Livingstone is making good progress after an ankle injury and is inked into England's middle order.
With Dawid Malan reaffirming his status as England's first-choice No. 3 in the decider in Lahore on Sunday night, the main question around their batting line-up concerns the identity of Buttler's opening partner. Alex Hales' experience in Australia means he is the favourite, but Phil Salt's form in Lahore means the debate remains live.
"That's the big question," Mott said. "I don't think that's resolved, which is probably not a bad thing. We've got four games before that first World Cup game [including a warm-up against Pakistan in Brisbane] so there's still plenty of time. Hales did really well at the start [of the tour] but Salt really took his opportunities… he showed all the signs we're looking for. There's a lot of options there, which is a good headache to have."
England managed players' returns from injury carefully, with Chris Woakes and Mark Wood playing two games each after missing the whole home summer. Wood was initially due to play the decider in Lahore, but he was one of several England players to suffer some illness last week and the management decided against risking him.
"We probably talked him out of playing, to be honest," Mott said. "He always wants to play but we didn't want to take that risk. We're pretty happy with what he got through. He's one of those bowlers, the X-factor bowler. A bit like Jos, he could maybe have played the back end of the series but those two guys are hard to replace so we're trying to box a bit smarter and not take the risk on what is going to be a long campaign."