Ive just had a look and Thomas Cook now have some flights for 2015 form EM but not next year. It wasn't an option when we booked so you are probably right.
Its usually been a smallish plane, seats three on each side. When we went in May it was 2 at each side then a about 3, 4 or 5 in the middle depending where you were on the plane (can't be sure how many). It did feel as if they had crammed more in as it was the most cramped seating I've been on.
We used Balkan for nine years and had two flights per year. The last three years they have consolidated all of them, even at August bank holiday last year. It hasn't been as bad if they told us as sometimes bt they don't always. We have asked to get on at Doncaster rather than drive to EM to fly back to Doncaster to head out to Bulgaria. We live close to Doncaster so have flown EM, Donny and Manchester.
Last year Balkan waited until a few weeks before our fight then asked us to transfer to Manchester Friday afternoon. We avoid motorways Friday afternoon/teatime so there is no way were were trying to travel to Manchester from here the Friday of a bank holiday weekend. The alternatives we were offered were Leeds/ Bradford or Humberside but both were bad flight times and expensive in taxis and weren't our chosen travel date. We asked if we could go on the Saturday flight from Manchester as there was still availability and it was cheaper anyway so we guessed not as popular or full. You would have thought we had asked for the moon on a stick! We got a really snotty email from one of the managers telling us no chance and a lot of bull. I told them the changes were too far away from our booking so I wanted a refund as per their policy. I told them I planned to book it again on their website at discount prices or with another company. After this they suddenly changed their mind. If they hadn't been so nasty in the email I wouldn't have minded. I think they forget without customers they don't have a business. Sorry to rant.