Condor and TCX are most likely holding onto the B753's for another few years in my opinion. It's a hard (verging on impossible) aircraft to replace from an operability and costs perspective. While the B752 is a hard aircraft to replace, the B753 is an even harder act to follow. The lease maturity profile favours the replacement of the current TCX A32X fleet and the B752's. The B753's are generally owned rather than leased so no pressing need to do anything with them.
Either way, I'm sure Jet2 will only pick up B737's or B757's at the right price.
Just my two cents...