A: John is a better player than Martin, isn't he?
B: Oh, yes. _______ the match tomorrow, I expect.
1) He will win
2) He is going to win
Which one is preferable here? (Me: #1 is better than #2.)
Source: Destination, B1
I agree with you. Using 'expect' indicates that it is just a mere prediction.
Here is another one:
A: What do you want to be when you grow up, Stevie?
B: _____ a scientist. That's what I want to do, anyway.
1) I will be
2) I am going to be
Source: Destination, B1 level
(Me: #2 is better than #1 here.)
Here, I also agree with you. Using 'That's what I want to do, anyway' indicates that it is a strong intention.