After the submission of a new payout method, your future payouts will automatically be processed to the new preferred payout method. However, this change will not apply to the bookings which have already been accepted, only future ones.
If you have a payout that is on hold, it will be processed to the payout method you had at the time the booking was accepted. This is unless you let us know in advance that you are intending to change your preferred payout method.