When there is an information vacuum, rumour will fill the space, that the basis of PPRUNE!
As it happens, SmartLynx have published the plot for their frames and CWL doesn't feature.
As with all thing in aviation, it could change at any moment and they miraculously acquire another one, but I think not.
TCX will obviously use an a/c they are familiar with and since they can't sell the seats on a 321 at cwl, let alone a 757, 320 has to be the option. The question is, which operator. 8 weeks to the opening of summer and no one is appointed. That is odd, not unprecedented, but odd.