But I do imagine that we will see R2-D2 having the stolen plans uploaded to his memory.
In fact this is what Leia does in the opening scene of ANH. Leia has the plan when the movie begins, she uploads them into R2 after having recording her message to Ben.
Jokes aside, I do think we’ll see the plans handed off to Leia at the end. We won’t see her, but the audience will know who it is.