Just by way of an aside, BA Cityflyer are doing a reasonable number of charters of their own, well in excess of the few operated for JOTA (on JOTA callsigns)
The company have always done charters, but generally these have been a full series on behalf of your operators at weekends. Big difference now being the current spare capacity allows scope for ad-hoc charters, and for these to routinely be planned during the week.