Last time I flew that route it was an MD11. However, I understand the roll-out of the new seats is fairly slow. It may be worth you giving AY Reservations a call and asking them – I would just add that AY do have a tendency to change aircraft at the last minute, so there probably won’t be any guarantees.
If you do get the new lie-flats, I’d be fascinated to know what you think of them.
I tried the new Via Lounge and Spa at HEL a couple of weeks ago – absolutely excellent.
Have a safe and fun journey!