It's a bit pathetic (from the airline's point of view, not the traveller's) that people have to try and gamble to see if they'll get to fly on the one aircraft EI has fitted with PTVs.
However, if EI gets new US access as a result of EU/US negotiations, it has already said it will add three new destinations within three months, so things may have changed by October. The problem is that it will be very difficult to get 332s at such short notice. Very interesting - and hopefully good - times ahead for EI.