Unfortunately Buffymad, it is likely that CAFCASS are understaffed. It is a sad fact that the cuts have meant that this is an area which has suffered. It is possible the officer will be able to see your BF and get his report done before the hearing. If not, it is likely that the Judge will attempt an interim resolution pending completion of the report. It is palpably unlikely that a final resolution will happen without a CAFCASS recommendation. Your BF should still attend Court UNLESS he receives notification FROM THE COURT that the case has been put back.
Unlikely that the hearing will be postponed pending police investigation - particularly if it a very old matter. The Family Court is more concerned with going forwards not backwards.
This is not my area, I just speak from long personal experience of this.