I just made a K fare reservation for BRU for late July, and before having it ticketed I asked the nice OP agent how it looked for availabiltiy to upgrade to BF, and was told 'very good'. She then proceeded to put me on the waitlist, and noted once again 'oh, you should have no problem, as you're Platinum and there's only one person ahead of you on the list!'.... Now I know there's been lots of discussions of buying a HoKeY ticket and there not being seats available etc, etc., but from this experience (as well as others I've had in the past), if you ask nicely, and you get the right OP agent-- they'll let you know prior to booking.