Bear in mind that only 60% of seats are available to choose from ahead of OLCI, and from my own experience, and what I've heard from others on here, it seems only 6 seats in the bubble are included (22-24HK, would be interested if anyone has seen any different though).
That said, the emerging view is that the bubble is not all it used to be, now that it's split with Y, and downstairs at the back (18-19AC) is a better place to be.
I hope that's true anyway, as I'm in those seats in April myself!