As much as I personally would like to see 3 A321's next year, I'm not sure if this will be the case.
On the outbound to Dalaman on 19/08 there were several empty seats (this despite it being peak season). Granted, TCX (and NCL in general) has a lot of seats to Dalaman and the return on 28/08, also the A320, was jam packed however I think the current set up is working well for TCX and other bases (BHX) are going Airbus next year too so these will probably need the A321's.
Also, the leased A320 has been a pretty good performer this year compared to last with very few delays so I personally can see it sticking around for a while